Preheat oven to 325
Cook quinoa according to package directions (bring water & quinoa to boil, simmer for 15 min)
Saute onions (and mushrooms) in butter.
Add Rotel, cream of mushroom soup and salsa. Simmer for 5 minutes.
Add sherry and simmer for 10 minutes
Fill peppers and set in baking dish.
Add reserved rotel liquid to remain quinoa mixture. Pour thinned mixture around filled peppers.
Cover with shredded cheese and bake for 30 minutes.