Summer Squash Soup with Basil

A delicious way to use your end-of summer bounty of squash! It would also be delicious served chilled.

Ingredients:
2 tablespoons olive oil
1 1/4 pounds zucchini, crookneck or pattypan squash, roughly chopped
1 large onion, chopped
6 cups Summer Vegetable Stock
1/2 cup julienned basil
1 1/2 tablespoons butter, softened
1 1/2 tablespoons flour
Salt and freshly ground pepper to taste
Juice of 1 lemon
Sour cream or plain yogurt as an accompaniment

Directions:
Heat the oil in a large saucepan or stockpot, add zucchini and onion. Sauté for 5 minutes or until onions are translucent and zucchini is crisp tender. Then add stock, bring to a boil, reduce heat and partially cover and cook for 25 minutes. Add basil during the last 5 minutes of cooking. Mix the butter and flour together into a paste. Remove 1 cup of simmering stock and whisk in butter mixture until smooth. Add back into soup, stir until thickened. Remove soup from heat to a blender and puree until smooth. Taste and season with salt and pepper. Add lemon juice and serve with a dollop of sour cream or yogurt.

From Curtis Aikens at http://www.foodnetwork.com