Butternut Squash And Asian Pear Soup

In a large pot or dutch oven, heat olive oil over medium high heat. Add onion and saute until translucent, about five minutes. Add the diced squash and pear and saute another five minutes. Add enough of the stock and/or water to cover the vegetables and bring to a boil. Add a teaspoon of salt, a few grinds of fresh cracked pepper, the leaves from the sprigs of thyme (or tie the sprigs together and add the bundle to the soup), the orange zest, the orange juice, half the lime zest, and half the lime juice. Reduce heat to low, cover and simmer the soup until the squash is tender, about 20 minutes. Remove from the heat, and at this point you can either use an immersion blender directly in the pot to puree the soup or transfer the soup to a blender or food processor--in batches if necessary--to puree the soup. Adjust seasonings with salt and pepper to taste. Just before serving, add in half the lime zest and the lime juice. Serve immediately, garnishing each bowl with a small dollop of sour cream, the rest of the lime zest and a lime slice or two.