I feed my little guys a wide variety of foods (I have, let me see, seven different flake/pellet foods)....but the one that I use that I
think has helped induce a more romantic atmosphere is "Emerald Entree" frozen cubes from my LFS...they are San Francisco Bay Brand. It contains Artemia, mysis, krill, plankton, spinach, romaine and red leaf lettuce, spirulina....
I have read that when the barometric pressure drops (like before a big storm) that fish get "in the mood" and that by doing a large water change beforehand will simulate the effects of a large storm.....I don't know...sounds like a whacked out theory but I've noticed my cichlids get very lovey-dovey, dancing all over before storms...it's kinda cool. Also, if you feed them following the water change, it is like when the rain, in their natural habitat, rushes into the lake and brings foodstuffs with it. I don't know....it's worth a shot.
Light some candles before your next snow storm and throw in a food that they like and see what happens. Good luck!