pineapple on pizza
Any kind of pizza topped with pineapple, whether as chunks traditionally, or humorously slices or even whole. Humorously associated with the Food Atrocities pool, and the How to Torture an Italian meme due to how some people consider this combination disgusting.
The most common sort of pizza with pineapple on it is Hawaiian pizza, which pairs the pineapple with ham (or Canadian bacon/salami/etc), to the point where to many people 'Hawaiian pizza' is synonymous with 'Pineapple pizza'.