1. Add a new edible fungus to the game. When you eat it, it will either give you an amazing stat/health bonus or will badly poison you. The chances of getting good or bad effects is based on luck. (Bonus points if you add a rare psychedelic effect that messes with your vision in some way.)
2. Unrelated idea: the player may designate a single favorite food or beverage that when consumed, applies one of several possible bonuses at random. Could be an earned perk, or not.