Beef or Chicken Fajitas

It is widely known by my friends that I make the best fajitas on the planet. This is not a braggie thing, my mom discovered a recipe in a newspaper before fajitas were really a thing and we've been making them this way ever since. You won't be sorry if you look for actual skirt steak. It's easy to find at most grocery stores that have a good meat dept. We throw a mean cinco de mayo party every year. It's just an excuse to serve these fajitas. We also make them for 4th of July or anytime we feel like great fajitas.

3 lbs skirt steak (or flank steak, boneless chicken breasts)
2 cups soy sauce
1 cup brown sugar
1 TB lemon juice
1 TB garlic powder
1 tsp black pepper
1 TB oil

Mix everything except steak together in a jar or tupperware container. Let sit for 24 hours. Pour over meat and marinate overnight up to 24 hours. Grill over very very hot coals or heat on a gril until temperature of meat is about 135. Bring inside and let meat rest for 15 minutes tented with foil. Slice as thinly as you can and serve with cooked onions, peppers, cheese, sour cream, guacamole, tomatoes and olives wrapped in warm flour tortillas. Serve a salad and spanish rice on the side. (If you do chicken make sure your internal temperature reaches 165 before taking it off the grill.