Pupusas Revueltas

1 lb chicken breast, ground
1 Tbsp vegetable oil
1/2 lb lowfat mozzarella cheese, grated
1/2 small onion, finely diced
1 clove garlic, minced
1 medium green pepper, seeded, minced
1 small tomato, finely chopped
1/2 tsp salt
5 C instant corn flour (masa harina)
6 C water