Dice your onion small, the finer, the better. Half and cut your tomato into thin slices. Cut your panini breads lengthwise into two.
½ Onion, ½ Tomato
Top each panini bread bottom with onion, tomato, salt, black pepper, ham, and cheese. Close the panini with the bread topping.
½ Onion, ½ Tomato, 4 Panini Bread, 2-4 Ham Slices, pinch Salt, pinch Black Pepper, 4 Cheese Slices
Heat a panini press or a skillet over the stove top. If you use the panini press, place the panini into the press to prepare the hot toasted sandwich. To make them on the stove top, heat the skillet and place the sandwich in, and press down the sandwich with another clean flat skillet. Flip the panini and repeat the pressing down with the 2nd skillet.
Serve up each skillet with your favorite dipping sauce.