Anchovies work. Try with just tomato sauce and cheese, onions and olives. It's a complex, mature type of taste. Maybe sun dried tomatoes. But it depends a lot on who's cooking it if you know what I mean.

You know how kids all go crazy about candy? That's because of how their taste buds work when they're kids. When you get older, these funky tastes get more like candy to us. Very rich flavors.