1 lb lean (at least 80%) ground beef 1 large onion, chopped (1 cup) 1/2 teaspoon salt 1 cup shredded Cheddar cheese (4 oz) 1/2 cup Original Bisquick mix 1 cup milk 2 eggs Heat oven to 400°F. Spray a 9-inch glass pie plate with cooking spray. In a 10-inch skillet, cook beef and onion…