Butter the insides and outsides of the bread.
Assemble each of the sandwiches by spooning marinara sauce on the bottom slice, then layering a slice of cheese, tomato slice, chicken and another slice of cheese.
Add top of bread to the sandwich.
Heat the grill and place the sandwiches on the grill over direct heat for two minutes, carefully flip and let the other side cook for two minutes.
Move the sandwiches over indirect heat, place the foil-wrapped brick on top and let the Panini finish cooking.
Once cheese has melted, remove from the grill and serve paninis with chips, veggies or fresh fruit.