Chef John's Curry Coconut Flap Steak

Combine curry paste, fish sauce, rice vinegar, coconut milk, black pepper, cayenne pepper, and salt in a large shallow glass or ceramic container. Mix well to create a uniform blend. Add the flap steak and gently toss to coat it evenly with the marinade. Cover the container with plastic wrap and refrigerate for 4 to 12 hours.

Next, remove the flap meat from the marinade and shake off any excess. Discard the remaining marinade, leaving only the meat behind.

To cook the flap steak, preheat an outdoor grill to high heat and lightly brush it with oil. Place the flap steak on the preheated grill and cook until it begins to firm up, develops a reddish-pink color, and remains juicy in the center. Cooking time will vary depending on the thickness of the meat; aim for 2 to 3 minutes per side. Use an instant-read thermometer to check the internal temperature, aiming for 130 degrees F (54 degrees C). Once cooked, transfer the meat to a plate and let it rest for at least five minutes before slicing against the grain.