Cut sausages lengthwise into halves. In a large skillet, over medium heat, cook sausages 8 to 10 minutes; drain. Increase the heat to medium high and add the green peppers; brown both lightly, 3 to 5 minutes. Remove the sausages from the pan and lay them out flat. Slice open the sub roll; spread sauce evenly and place sausages flat on bun. Sprinkle evenly with green pepper and mozzarella cheese; place, open side up, under a broiler for 2 to 3 minutes or just until cheese is melted. Remove from the broiler; close the sandwich and serve hot.

Note: Fresh sausage should always be cooked to well done.