In large skillet, cook chipped steak with onion until meat is no longer pink. Break up meat with spatula and drain meat.
Lightly grease an 11" x 14" cookie sheet. Gently spread dough out on cookie sheet to a rectangle about 1/4" to 1/2" thick. Spoon ricotta cheese down the middle lengthwise. Arrange cooked chipped steak/onion mix on top. Top with green peppers and mushrooms (if using them). Top with slices of American cheese. Gently fold long ends together, pressing down seams to seal. Bake at 400 for about 20 minutes or until lightly brown.