preheat oven to 350

place sliced squash and onion in large sauce pan then fill with water.VERY IMPORTANT to do it this way as the squash floats in water

drain cooked squash, then place into large bowl

mash cooked squash mixture with potato masher or back of large spoon

now drain squash again, and place into a greased 9x13 cake pan

in large bowl mix cream of celery and sour cream and a little salt and pepper

then add dry stuffing, mix to combine

place on top of squash mixture in pan

sprinkle with cheese

bake at 350 uncovered for 35-45 mins