First you want to make your marinade.
In a gallon ziplock bag combine:
Juice of one lime
1/4 cup olive oil
1 tsp kosher salt
1 tsp black pepper
1/2 tsp chili powder
Rub London broil with:
1 tsp chili powder
1 tsp garlic powder
Place in ziplock bag, shake it up, and let sit at room temperature while you prepare sauce and salad. (About 30 minutes)
Heat propane grill. Allow at least 10-15 minutes for it to get hot.
Take London broil out of marinade, place on grill. Then spread 1 tablespoon softened butter on top. Close lid and allow to cook about 4-5 minutes.
Flip! Cook an additional 4 minutes.
Temperature with meat thermometer should read 145 degrees for medium rare.
Take off grill, allow to stand 5 minutes before slicing.
Slice, top with chimichurri, serve with salad and ENJOY! (Then come back to let me know if you how you liked it!)