Eggs: Grill eggs whole in their shells over indirect heat until the shells are brown, turning occasionally, about 25 minutes. Drop in a bowl of ice water before cracking them open.
Mozzarella: Start with part-skim mozzarella--whole-milk mozzarella is too moist to grill--and pat it dry thoroughly with a paper towel; if it's too moist, it'll melt too soon. Put the cheese on the grill over indirect heat for a few seconds, then flip and repeat. Watch carefully so it doesn't melt too much.
Grapes: Grill grapes directly on the grill grates over indirect heat. Watch carefully so they don't burn.
Frozen Onion Rings: Place frozen onion rings directly on the grill over medium heat for 5 to 8 minutes. Flip with metal tongs and cook until golden brown, another 5 to 8 minutes.
Frozen French Fries: Place frozen fries directly on the grill over medium heat and grill, flipping, until cooked through. You can also loosely wrap frozen fries in a sheet of foil and put the packet on the grill over indirect heat for 2 to 3 minutes per side.
Cookie Dough: Place cookie dough balls on a sheet of foil on the grill. Grill with indirect heat on a covered grill for 8 to 9 minutes; try to keep the temperature near 350 degrees F until they're cooked through.