Nonstick cooking spray
1 16 ounce package shelf-stable potato gnocchi
1 1/2 cups light or no-sugar-added tomato-base pasta sauce
12 ounces extra-lean ground beef
1/4 cup finely chopped onion
1 small egg, lightly beaten, or 2 tablespoons refrigerated or frozen egg product, thawed
2 tablespoons fine dry whole wheat bread crumbs
1/2 teaspoon dried oregano, crushed
1/2 teaspoon dried basil, crushed
1/4 teaspoon garlic powder
1/4 teaspoon fennel seeds, crushed
2 teaspoons olive oil
8 ounces fresh mushrooms, sliced
1 medium green sweet pepper, stemmed, seeded, and cut into bite-size strips
1/2 cup thinly sliced onion
2 teaspoons olive oil
1/2 cup shredded part-skim mozzarella cheese (2 ounces)