Spiced Apple and Butternut Squash Soup

1/4 cup butter
2 large onions
2 large Granny Smith apples
     peeled, cored, and diced
1 tsp. nutmeg
1/2 tsp. allspice
1/2 tsp. cinnamon
2 large butternut squashes
     peeled, halved lengthwise and seeds removed,
     diced into 1-inch cubes 
(recipe called for 4 squashes but once I had two prepped it was obvious I was using larger ones than they called for)
3 qts. chicken stock
Salt and pepper to taste

Melt the butter in a large pot over medium heat.  Add the diced onions and apples and cook until tender, about 10 minutes.  Stir in the spices and cook for 1 minute.  Then add the squash and chicken stock.  Bring to a boil.  Reduce heat and simmer, uncovered, until the squash is tender, about 20 to 30 minutes.

Puree and serve.  Add additional stock if necessary to desired thickness.