Serve 'em cheeseburgers with all the fixin's they like—along with a custom-made condiment made with Thousand Island dressing and real mayonnaise. Heat grill to medium-high heat.Shape meat into 4 (1/2-inch-thick) patties. Grill 5 to 6 min. on each side or until done (160°F). Top with cheese; grill 1 min. or unti….