Improving cultivation of more types of mushroom would do a lot.

The range of tastes in mushrooms varies a lot more than most people realise - it drives me crazy how many English words are used for the same mushroom (portobello, white, brown, chestnut, crimini, champignon all refer to agaricus bisporus), and how few mushroom varieties most people have tasted.

Especially as A.bisporus is one of the most boring mushrooms in existence.