Place squash, onions and carrots in microwavable casserole dish, add about 1/4 cup water, cover with plastic wrap and vent corner. Cook on high 5 minutes.
Drain water off, add cream of mushroom and ricotta cheese and spices. Stir together and microwave uncovered 5 minutes Take out and stir in cheddar cheese. Then top with crushed croutons, put back in microwave for 1 minute.