Mix the half the avocado oil, lime juice and zest, chilies and seasonings together in a shallow dish. Add the meat and marinate overnight for best flavor.

Drain the meat. Preheat a grill or grill pan to medium-high heat.

If using a grill, place the meat in a grill basket, sprayed with cooking spray, and cook for 5 to 12 minutes, or until tender. If using a grill pan, cook 2-3 minutes, then flip and cook to desired temperature. 

Transfer to a plate and cover to keep warm.

Bring a wide skillet to medium heat. Add other half of the oil.

Cook vegetables for 8 to 12 minutes, until tender, stirring frequently.

Slice the meat into thin strips, on the bias, with a sharp knife.

Serve the meat and veggies with the butterhead lettuce as "wraps."