Summer Squash and Corn Chowder

My boy's coworker has been giving us so much squash that I didn't know what to do with it. I finally got down to business last night and, after not finding a recipe I completely liked online or in my cookbooks, I more or less made up this one. It was delicious, tasting sweet and spicy at the same time. I'd love to make it again--now, bring on the squash!

Summer Squash and Corn Chowder

1 pound yellow summer squash
2 ears corn
3 shallots
3 garlic cloves
1 tablespoon olive oil
1/2 teaspoon ground cumin (more to taste)
1/2 teaspoon red pepper flakes
Dash of cayenne red pepper
Salt and pepper to taste
2 cups vegetable stock
3 tablespoons butter

Wash and chop squash crosswise into 1/2 inch thick pieces. Shuck corn and cut kernels from cobs. Chop shallots and mince garlic.
In a large soup pot, combine squash, corn, shallots, garlic, olive oil, and spices, and cook over medium heat for ~4 minutes. Stir in vegetable stock and simmer the mixture until squash is very soft, ~ 15 minutes. Using an immersion blender, puree the mixture until semi-smooth (chowder consistency). Stir butter into mixture until it melts and is blended evenly.
Serve warm, topped with plain yogurt. Serves ~2.