I've shared this one before, but since this is a grilled cheese specific thread:
Bread -- something dense like ciabatta.
Fat -- olive oil (not extra virgin, that should never be cooked with as it has a very low smoke point and oils generally take on a bitter flavor once they start to smoke).
Cheese -- gouda.
Toping -- tomato.
Spices/other -- fresh ground black pepper, garlic salt, basil, balsamic vinegar.
Process:
-- Slice bread apx. 1/2 inch thick, set aside. Heat olive oil on medium/medium-low heat in a medium sauce pan. Slice tomatoes (enough to fully cover bread) and introduce into saucepan, season with garlic salt and a generous amount of basil.
-- While tomatoes are sauteing slice cheese apx. 1/4 inch thick to cover bread. In a plate (I just use waxed paper plates to ease cleanup) drizzle olive oil to cover the bottom. Dip one side of bread in the oil while drizzling balsamic vinegar on the other. Season oiled side of bread with garlic salt and black pepper.
-- Introduce the first slice of bread to a skillet on medium heat (gouda has a high melt point so it has to be heated slowly to prevent bread from burning), cover bread with cheese, then add tomatoes, and finally the top slice of bread.
-- Cook each side to even golden-brown.
-- Win.
Yeah, it's a pain in the ass and takes longer than any grilled cheese really should -- I've gotten the process down to about 12 minutes -- but it's fucking delicious.