If you are making a few at a time, lay all the bread slices out on a rimmed baking sheet, and build all the sammies there in an assembly line. You can make just one, or six, just scale up or down with the leftover ingredients.

A true panini would be pressed, so you have the option to use the actual tool for pressing, or do them in a pan with weight on top, or just do them batched in the oven and at least they’ll be warm. Directions below.