2 lbs. lean ground beef 2/3 cup onions, diced 2 tsp grill seasoning, see notes 2 tbsp butter 2 tbsp all-purpose flour 3/4 cup milk, 2% or whole 8 oz. sharp cheddar cheese, grated 1 frozen seasoned curly fries, 20 to 28 oz bag For the Fry Sauce: 1/4 cup ketchup 1/4 cup mayo Hot…