Summer Squash Soup

I let my enthusiasm carry me away at the farmers market, so we have more squash than we need. Tonight I made squash soup, which is fairly simple, but tasty:

2 T. olive oil
1/2 tsp. coriander
1 tsp. cumin
2 lbs. summer squash, cut into dice
1 small onion, minced
2-3 small cloves garlic, minced
1/2 serrano or one whole (small) jalapeño pepper, chopped fine
1 small red or yellow pepper or a carrot, minced
1 1/2 c. chicken broth
1 T. sour cream
salt and pepper
chopped herbs (cilantro, basil, or parsley) for garnish

Sauté the onions in the oil, add the spices and cook one minute, then add the garlic and peppers and sauté for 3-5 minutes. Add the diced squash and let that cook until slightly softened, about 5 minutes. Add the broth. Cover and let simmer until the squash and peppers are soft. Then purée the soup in a blender with the sour cream. Add salt and pepper to taste. I like this soup a little spicy, so I also put in red pepper flakes, and you could add other garnishes like crumbled feta or cooked corn.