Ways to counter the burn of too many scallions?
Cauliflower fritters. Mix some egg, ice-cold water and flour, then stir in the other ingredients. Gently put about one or two tablespoons at a time into a deep-fryer using two spoons. We do something similar to make "kaki-age", which is a mix of vegetables prepared using a batter similar to tempura, and generally includes onion. You can probably also get away with doing this in a frying pan with just the bottom covered in oil if you keep the oil temperature stable enough.

For what it's worth, I prefer to make mashed potatoes by ricing them then adding butter, milk, scallions and cream then letting them roast for a while in an enameled cast-iron pot. I've never noticed an unpleasantly raw taste with the scallions in this way. Perhaps a similar approach would work for the cauliflower.