Beef Noodle Casserole

Name: Beef Noodle Casserole
Ingredients: 1 tablespoon plus 1/2 teaspoon kosher salt , divided, plus more to taste; 2 tablespoons extra virgin olive oil; 1 medium white onion, chopped (1 1/2 cups); 1 bell pepper , seeded, ribs removed, finely chopped, about 1 cup; 3 cloves garlic, minced, about 1 tablespoon; 1 (28-ounce) can whole peeled or crushed tomatoes; 1 1/2 pounds ground beef; 4 ounces mushrooms, sliced; 12 ounces egg noodles; 1 1/2 cups frozen corn, defrosted; 1 (15-ounce) can black olives , strained and chopped; 8 ounces cheddar cheese, grated