Preheat oven to 350 degrees. Bring 3 cups water and 1 teaspoon salt to a boil in 2 quart saucepan over medium-high heat. Whisk in cornmeal, reduce heat to low, and simmer, whisking constantly, 3 minutes or until thickened. Remove from heat, and stir in steak seasoning and 1/4 cup Cheddar cheese. Spread cornmeal mixture into a lightly greased 11 x 7 -inch baking dish.
Brown ground chuck in a large non-stick skillet over medium heat, stirring often, 10 minutes or until meat crumbles and is no longer pink; drain and transfer to a bowl.
Saute onion and zucchini in hot oil in skillet over medium heat 5 minutes or until crisp-tender. Stir in beef, tomatoes, and tomato paste; simmer, stirring often 10 minutes. Pour beef mixture over cornmeal crust. Sprinkle with remaining 3/4 cup cheese.
Bake at 350 degrees for 30 minutes or until bubbly. Sprinkle casserole with parsley just before serving.