Preheat your Z Grills Pellet Grill (preferably with branded wood pellets) or other wood pellet grill to 350 degrees Fahrenheit.
Place the grill pan or skillet on the grill and close the grill to preheat.
Meanwhile, butter the outside of each slice of bread.
Combine the cheese and garlic in a bowl, then divide the cheese between the slices of bread. Follow with the ham and sliced tomato, if using. Close each sandwich.
Transfer the sandwiches to the grill pan or skillet. Use a grill press to flatten the sandwiches.
Close the grill’s lid and cook for 3 minutes.
Uncover, flip the sandwiches, and grill for another 3 minutes.
Remove the sandwiches from the grill and serve.