This soup is especially nice garnished with rye or sourdough croutons.
1 pound potatoes, cut into 2-inch pieces
1 tablespoon plus 1 1/2 teaspoon olive oil, divided
salt and freshly ground black pepper to taste
1/2 cup leeks, thinly sliced
3 cups vegetable stock
3 sage leaves, chiffonade
Preheat oven to 400 degrees F. Toss potatoes with 1 tablespoon of olive oil, salt, and pepper. Roast for 20 to 25 minutes.
In a soup pot, sauté leeks in 1 1/2 teaspoons of olive oil for 2 to 3 minutes. Add roasted potatoes and stock. Bring to a boil, reduce heat, and simmer, uncovered, for about 30 minutes. Transfer soup solids to a food processor, adding about half the stock and process to make a smooth purée. Return the purée to the pot, stir well to incorporate it into the remaining stock, and add sage. Adjust the seasonings to taste.
Warm over low heat for 5 to 10 minutes and serve immediately.
Adapted from http://www.epicurious.com/recipes/member/views/ROASTED-POTATO-BISQUE-WITH-LEEKS-AND-SAGE-1247335#ixzz1ZYllCA2I