Heat 1 tablespoon oil in a large ovenproof skillet over medium-high heat. Add 1 cup onion, the chopped bell pepper and the chopped mushrooms; cook, stirring occasionally, until tender and lightly browned, about 10 minutes.
Stir in 2 tablespoons tomato paste, the minced garlic and 2 teaspoons garlic-and-herb seasoning; cook, stirring constantly, until the tomato paste darkens slightly, about 1 minute. Add ½ cup water; stir, scraping up any browned bits from the bottom of the pan.
Stir in rinsed beans, 1 can tomato sauce, 2 tablespoons basil, 1 tablespoon oregano, ¾ teaspoon salt, ½ teaspoon pepper and the remaining ¼ cup water. Bring to a gentle simmer. Reduce heat to maintain a gentle simmer and cook, stirring occasionally, until slightly thickened, 5 to 7 minutes.
Meanwhile, preheat broiler with a rack in the upper third of the oven. Sprinkle the mixture in the skillet with 1 cup mozzarella. Broil until the cheese is melted and lightly browned, about 4 minutes. Garnish with additional basil, if desired.
