It’s Passover. That means eight days of eating matzoh, which gets me thinking about products that are complements with or substitutes for matzoh. Butter or margarine, and salt, are clearly complements-spread and salt the top of a piece of matzoh, and you have a great snack. Gefilte fish (ground whitefish, carp and pike, spiced up, and then boiled) is surely a complement, as is horseradish (hopefully strong enough to cause eyes to tear). Honey and apples and nuts are too. The substitutes are typically the things proscribed on religious or cultural grounds during Passover, including bread products and legumes.
Prunes are also a complement for matzoh, but not for religious or cultural reasons.