Prepare 2 slices of bread.
Slice 30g of Gouda cheese.
Thinly slice 20g of lettuce and 30g of tomato.
Place the lettuce, tomato, and Gouda cheese in order on one slice of bread.
Cover with the other slice of bread.
Melt 5g of butter in a pan.
Grill the sandwich until golden brown on both sides.
Cut the finished sandwich in half.