Press the garlic cloves through the garlic press. Coarsely grate the Gouda and mix in a bowl with the garlic and a dollop (start with approx. 3 tablespoons, possibly more) tartar sauce. It should produce a sticky mass. If possible, this should sit in the refrigerator for a while.
Cut the tomatoes (preferably large beefsteak tomatoes) into slices about 1 cm thick. Cover each tomato slice with about a heaping tablespoon of the cheese mixture.