I use a cast iron griddle to grill the sandwiches but a sandwich maker or frying pan would work just as well.
Step 1: The Foundation
Whole wheat multi-grain bread: two pieces per sandwich.
Provolone cheese, thinly sliced: enough to cover one piece of bread twice. The amount depends on the length and width of each slice.
Roma tomatoes: enough to over the surface of the slice of bread. Again, it varies on the size of the tomato and the size of the piece of bread.
Basil: see tomato quantities.
Butter: to melt sparingly onto the hot surface of the griddle or frying pan.