Heat oven to 425. Mix baking mix and yeast, stir in water and beat vigorously. Turn dough onto well-floured surface, knead until smooth about 20 times. Let dough rest a few minutes.
While dough is resting, dip container of frozen mix into hot water just to loosen. In 2-quart saucepan, heat frozen mix and remaining ingredients to boiling. Reduce heat, cover and simmer, stirring frequently.
Spoon onto bottom halves of buns, tip with remaining halves. Divide dough in half. Roll each half on ungreased baking sheet into rectangle 13x10 inches or on pizza pan into 12-inch circle. Pinch edges to make a slight rim.
Spread meat mixture almost to edges. Top with green pepper and cheeses. Bake until crust is brown and filling is hot and bubbly, 15 to 20 minutes. Cut into squares or wedges.
