Tomato ‘n’ Beef Casserole With Polenta Crust

Ingredients:

• 1 teaspoon salt
• 1 cup plain yellow cornmeal
• 1/2 teaspoon Montreal steak seasoning
• 1 cup (4 oz.) shredded sharp Cheddar cheese, divided
• 1 pound ground chuck
• 1 cup chopped onion
• 1 medium zucchini, cut in half lengthwise and sliced (about 2 cups)
• 1 tablespoon olive oil
• 2 (14 1/2-oz.) cans petite diced tomatoes, drained
• 1 (6-oz.) can tomato paste
• 2 tablespoons chopped fresh flat-leaf parsley