Meanwhile, in 12-inch nonstick skillet, heat remaining 2 teaspoons oil over medium-high heat. Add mushrooms and remaining 1/4 teaspoon salt. Cut sausage casing, and discard. Crumble sausage into skillet with mushrooms. Cook 8 to 10 minutes, stirring occasionally to break up sausage, until sausage is no longer pink. Stir in bell pepper and remaining 2 teaspoons garlic; cook 1 to 2 minutes or until garlic is fragrant. Stir in tomatoes; heat 3 to 4 minutes or until heated through.