That “caviar” dish you had is ikra (which translates, literally, as caviar). There’s a whole set of similar vegetable dishes called ikra, usually with some adjective at the front that Russians drop off “because everyone understands it already.” Bakhlazhanaya ikra is zuchini caviar, for example (fine chopped zuchin, carrots, and onions cooked together in sunflower oil with a bit of salt: one of the really good things you can make with those zepplin-sized zuchini in the garden). Add eggplant and it’s another variety. What it sounds like you had probably was the eggplant variety with bulgarian red pepper (sweet red bell pepper). In a restaurant, it would be a small side dish on the plate, but spreading it on bread is no more gauche that doing the same with red caviar (krasnaya ikra: caviar from salmon eggs, which is caviar for normal people instead of the beluga caviar from the Volga delta which costs obscene amounts of money).