4-6 inches of a ciabatta (1/2 of a demi ciabatta) cut in half
aged gouda (enough to cover the tomatoes)
I chose aged gouda because the flavor is much stronger and more pronounced.
I drizzled the bread with some olive oil and put it under the broiler for a couple of minutes, until the bread was just starting to brown. I thinly sliced a tomato and put it on the bread. I used a vegetable peeler (although I imagine a cheese plane would have worked better) to get a few slices of cheese. It is quite a hard cheese, so the slices came out paper thin. After putting the cheese on top of the tomato (which was seasoned with tomato's best friends - salt and pepper) I put it back under the broiler until the cheese melted.
The sandwich was very tasty - the only problem came when attempting to eat it open-face. The tomatoes do not stick very well to the bread and have a tendency to come off with each bite. I remedied this by closing it up, squishing it a little bit, and eating it up.