Flank steak is a wonderful protein because it's relatively cheap but can be incredibly flavorful. It's important to cook it correctly to keep the meat from becoming too tough. Marinating the meat is one of the best things you can do!
Technique tip: Rest grilled steak under foil before slicing for the most tender results.
Swap option: Not a big fan of spicy foods? Use poblano or bell pepper instead of jalapeno peppers for less heat.
Combine the vinegar, garlic, shallots, jalapeno, parsley and red chili flakes in a medium-sized mixing bowl. Whisk in the olive oil and season with salt and pepper.2.
Move flank steak onto a tray. Season with salt and pepper on both sides.3.
Rub half of the marinade over the meat. Cover it and refrigerate for 8 hours.4.
When you're ready to start cooking, preheat the grill to 450 degrees.5.
Remove the meat from the fridge and allow it to get to room temperature, about 15 minutes.6.
Grill the meat on each side, turning to avoid over charring. Each side will take around 3 minutes for medium-rare. The internal temperature should reach 125 degrees.7.
Before serving, allow the meat to rest, tented with foil, for 30 minutes.8.
Slice against the grain and serve with the remaining marinade sauce.9.
Finish with sea salt, if desired.