A game we used to play when we were younger were to find 3 ingredients that did not taste good in any combination with each other. For example – chocolate, tuna and garlic. Chocolate and tuna are bad together, and chocolate and garlic are bad together but tuna and garlic can be good together.
Here’s another – strawberries, cheese and marshmellows. Strawberries and cheese don’t go. But strawberries and marshmellows do.
I don’t know if this is what you are looking for, but I nominate the unholy triad of onions, parsnips and turnips. Indivdually, I find them all abhorrent; any combination of two or more can only get worse…
Maybe we should limit ourselves to ingredients that we like individually–otherwise I could simply splice together herring, haggis, and brussels sprouts for a list that’s not only bad in any self-contained combination, but in combination with anything else.