I learned early that flank steak is one of the fastest ways to feed a crowd without spending hours at the grill. In my kitchen, this cut goes from fridge to table in under 20 minutes, and the real trick is pairing it with a fresh, creamy avocado chimichurri that cuts through the meat’s richness. I like how the herbs and lime bring a bright pop that makes each bite feel light and summery.
I’m a fan of simple seasoning and fast, hot grilling for flank — it rewards you with bold sear marks and juicy slices when treated right. I’ll walk you through my short prep, how I handle the chimichurri without turning the avocado into paste, and a couple of quick marinades if you want deeper flavor. These are tricks I use when I’m juggling guests, a pitcher of margaritas, and a short window of prime grilling weather.
When I serve this at home, I always slice the steak thin and against the grain, scatter the chimichurri over the top, and let the garnish do the work. The result is vivid green, fragrant herbs against a smoky brown steak — it looks way fancier than the time it took me to make it.
What You’ll Need to Make Grilled Flank Steak with Avocado Chimichurri
The ingredients are straightforward, but quality matters. Choose the freshest herbs and a good piece of flank steak — the meat’s flavor will shine through. The chimichurri is the bright partner to the steak’s richness, and you can swap herbs or acids depending on what you have on hand.
- Flank steak – The lean, long-grain cut that benefits from high heat and quick cooking; look for even thickness and good color.
- Olive oil – Helps the steak sear and keeps the chimichurri silky; use a neutral or extra-virgin depending on your preference.
- Salt and black pepper – Simple seasoning that brings out the beef’s natural flavor; season just before grilling.
- Avocado – Adds creaminess and body to the chimichurri; choose ripe but firm fruit so it holds shape when tossed.
- Cilantro – The green backbone of the chimichurri; swap parsley if you prefer a milder herb.
- Lime and red wine vinegar – Acidity brightens the chimichurri and prevents the avocado from tasting flat; balance them to taste.
- Red pepper flakes and garlic – Add a gentle heat and savory depth to the chimichurri; adjust to your heat tolerance.
- Flexible swaps – Try parsley, chives, or a touch of mint in place of some cilantro; use lemon if you don’t have limes.
For more tips on keeping avocado toppings fresh longer, see these notes on maintaining avocado dishes here.
Cook Grilled Flank Steak with Avocado Chimichurri — Step-by-Step
- Preheat your grill until it’s very hot so you get an immediate sear; high heat is what gives flank steak that caramelized exterior.
- Bring the steak to room temperature for a few minutes and pat it dry; rub a thin coating of oil on the surface and season both sides with salt and pepper so the seasoning adheres and forms a crust.
- Place the steak directly over the hottest part of the grill and cook until well-seared on one side, then flip and sear the other side. Aim for a quick cook so the inside remains medium-rare — use a meat thermometer to check doneness if you have one.
- Remove the steak from the grill when it reaches your target internal temperature and let it rest for about five minutes so the juices redistribute — this is the step that keeps the steak juicy when you slice it.
- While the steak rests, gently toss the diced avocado with chopped herbs, lime juice, a splash of vinegar, minced garlic, red pepper flakes, and a drizzle of oil. Toss carefully so the avocado keeps some texture instead of turning to mush.
- Slice the steak thinly against the grain and spoon the avocado chimichurri over the slices just before serving so the herbs stay bright and the avocado remains creamy.
Pro-Tips:
- Use a digital thermometer to hit your exact doneness — flank is best sliced thin at medium-rare to medium.
- Dry the steak thoroughly before seasoning; moisture on the surface prevents good browning.
- Slice against the grain for tender bites, and cut thin so each piece is easy to chew.
Troubleshooting:
- If the steak is tough, you likely overcooked it — next time reduce cooking time and rest properly.
- If the chimichurri turns brown quickly, keep it chilled and add acid right before serving to maintain brightness.
- If the avocado becomes mushy, use slightly firmer fruit and fold ingredients gently rather than pureeing.
Variations:
- Swap cilantro for parsley or a mix of herbs for a different herbaceous note.
- Add a touch of smoked paprika or cumin to the steak rub for a warm, smoky edge.
- Top with pickled onions or charred corn for extra texture and contrast.
How to Keep Flank Steak Tender (Timing, Temperature, and Rest)
I’ve learned the hard way that flank steak goes from perfect to chewy if you rush it. Timing and rest are everything; treat the meat gently after cooking and cut with intention. Below are simple, beginner-friendly guidelines and common pitfalls to avoid.
- Cook times: Flank is thin and benefits from a fast sear. Aim for quick, high-heat cooking rather than slow roasting.
- Target temperatures: Use a thermometer to pull the steak at your preferred doneness; this prevents overcooking and toughness.
- Resting: Let the steak rest for several minutes on a warm cutting board before slicing so juices redistribute — skipping this makes the steak dry.
- Common mistakes: Avoid slicing immediately, cutting with the grain, or letting the grill temperature dip mid-cook; each of these makes the meat seem tougher.
For more on basic tenderizing techniques and how low-and-slow differs from quick searing, check these practical tips here.
Keeping Avocado Chimichurri Bright and Creamy Without Mashing
The goal of the chimichurri is contrast: bright, herby acidity with creamy avocado chunks. I always use ripe-but-firm avocados and fold everything together gently so you still get those buttery bites.
- Choose avocados that yield slightly to pressure but aren’t squishy so they hold their shape when tossed.
- Combine acid (lime and a splash of vinegar) before adding avocado — it helps maintain color and keeps the flavor lively.
- Toss with a light hand: mix herbs, acid, and oil first, then fold in avocado at the end to preserve texture.
- Adjust salt and heat last; a brief chill keeps the herbs green but serve soon after assembling for best flavor.
More tips on keeping avocado dishes fresh are available here.
Quick Marinade Options and When to Use Them
Marinating flank can add flavor and a touch of tenderness, but because flank is thin, you don’t need long. Below I break down quick marinade profiles and when I reach for each — short marinating preserves the steak’s texture while boosting aromatics.
- Citrus-herb marinade: Bright and acidic; use for 30 minutes to a couple of hours when you want freshness and a little tenderization.
- Soy-ginger marinade: Umami-forward and slightly sweet; great for an Asian-leaning plate and quick flavor penetration.
- Garlic-red wine vinegar mix: Bold and aromatic; acid tenderizes but keep marinating time short or the texture will become mushy.
- Dry rub option: Salt, pepper, and smoked paprika or cumin — ideal when you want a clean sear without extra moisture from a wet marinade.
For a handy multipurpose marinade that complements many proteins, try this simple grilled chicken marinade that also works well with beef:
For a delicious flavor boost, try our grilled chicken marinade that works well with a variety of meats.
Tools and Grill Settings for Fast, Even Cooking
Having the right tools shortens the learning curve. I keep a small kit in my grilling drawer that gets the job done quickly: a reliable thermometer, tongs, a sturdy spatula, and a brush for cleaning the grates.
- Digital instant-read thermometer — the fastest way to perfect doneness.
- Tongs with a good grip — for flipping without piercing the meat.
- Clean, oiled grill grates — prevents sticking and promotes even searing.
- Gas vs. charcoal: Gas gives predictable heat and speed; charcoal adds smoky flavor but needs a bit more attention to maintain consistent searing temperature.
- Two-zone fire: If possible, set one side hot for searing and one side cooler to finish if needed; this prevents over-charring while you manage thicker ends.
Simple Sides to Serve with Grilled Flank Steak
Pair the steak with bright, easy sides that round out the meal without stealing the show. Think quick salads, grilled veg, or a starchy side to soak up chimichurri.
- Fresh garden salad with vinaigrette — a crisp counterpoint to the rich steak.
- Grilled vegetables (asparagus, peppers, zucchini) tossed with olive oil and salt.
- Charred corn or a simple rice pilaf — something to hold the chimichurri sauce.
- Crusty garlic bread or warm flatbreads to scoop up any leftover sauce.
Try adding one of my favorite quick salads to the plate for a balanced meal:
Elevate your meal with our simple salad pairings that complement grilled flank steak beautifully.
How to Store Your Grilled Flank Steak with Avocado Chimichurri
Leftovers can stay great for meal-prep if you store components separately. The steak keeps its texture better when sliced and chilled quickly; the chimichurri is best refrigerated in an airtight container.
- Store steak in a shallow airtight container and refrigerate within two hours of cooking.
- Keep chimichurri in a separate container so the avocado and herbs stay brighter longer.
- To reheat, warm steak gently in a skillet over medium-low heat or briefly under a broiler; avoid microwaving which can dry the meat.
- If you must freeze, slice the steak, vacuum-seal or tightly wrap portions, and thaw overnight in the fridge before reheating.
Make-Ahead and Meal-Prep Instructions for Flank Steak
When I plan ahead, I use short marinades and portion the steak for quick weeknight dinners. Batch cooking flank works well because it reheats predictably when sliced thin.
- Marinate briefly and refrigerate for a few hours before grilling if you want extra flavor; don’t exceed recommended marinating times for thin cuts.
- Cook a few steaks at once, slice against the grain, and portion into meal-sized containers for the week.
- Store chimichurri separately and add just before eating to keep the avocado and herbs fresh.
- Freeze cooked, sliced steak for longer storage; thaw overnight in the fridge before reheating gently.
Frequently Asked Questions
What is the best way to season flank steak?
A simple seasoning of salt and pepper works great, but you can also add garlic powder, onion powder, or your favorite spices for more flavor!
How long should I let flank steak rest after grilling?
Let the flank steak rest for about 5 minutes after grilling. This allows the juices to redistribute, ensuring a juicy and flavorful steak.
Can I make the avocado chimichurri ahead of time?
Yes, you can prepare the avocado chimichurri in advance! Just store it in an airtight container to keep it fresh, but it’s best enjoyed the same day.
What sides pair well with grilled flank steak?
Delicious sides include a fresh garden salad, grilled vegetables, or even some garlic bread. These will complement the flavors of the steak nicely!
Is marinating flank steak necessary?
While marinating flank steak isn’t necessary, it can enhance the flavor and tenderness. A couple of hours is usually enough for the marinade to work its magic!
Grilled Flank Steak with Avocado Chimichurri
Ingredients
Method
- Heat grill to high heat 400-450°F.
- Allow steak to come to room temperature. Season flank steak with salt and pepper on both sides.
- Place steak on grill and cook for 4-6 minutes per side. Internal temperature should be 130°F.
- Remove from grill, let sit for 5 minutes.
- While the steak is resting, make your avocado chimichurri. To a bowl, add diced avocado, cilantro, red wine vinegar, lime juice, red pepper flakes, garlic, and salt. Gently toss together to combine.
- Then slice steak against the grain and serve with avocado mixture.
- Serve with avocado chimichurri sauce.
