Cut chicken into cubes and season with chili powder, salt and pepper. Saute chicken until done.
Saute onion and green pepper until soft, 10-15 minutes.
Bake pizza crust 10-15 minutes, or according to package directions. Remove from oven and spread salsa over crust. Add onion and green pepper over salsa. Place chicken over pizza and top with Mexican cheese.
Bake at 350 until cheese melts, about 10-15 minutes.