1. Cut fennel sausages into 3 pieces each. In a nonreactive large frying pan, heat oil over medium heat. Add sausages and cook, turning, 10 minutes, or until browned and cooked through.
2. Spoon off fat from pan. Add onion and peppers. Cook, stirring, 5 minutes. Add tomatoes, water, salt, and pepper. Bring to a boil, reduce heat to low, cover, and cook 15 minutes. Stir in parsley. Spoon sausages with peppers and sauce onto split rolls