Garlic and Sweet Potato Soup

3 medium leeks -- trimmed and -- coarsely chopped

1 large head garlic -- cloves separated -- and peeled

3 pounds sweet potatoes -- peeled and cut -- into 1-inch chunks

8 cups chicken stock or water -- (up to 10) salt and freshly ground black pepper

1/2 cup crumbled feta cheese

1/4 cup finely chopped fresh chives In a large heavy pot heat

3 tablespoons oil and saute the leeks until tender, a bout

5 to 8 minutes. Reserve

3 large cloves of the garlic. Add the remaining ga rlic and sweet potatoes to the pot and stir to combine. Add enough chicken stoc k or water to barely cover the vegetables. Season with salt and pepper. Bring t o a boil, reduce heat and simmer until the sweet potatoes are very tender about 20 to 30 minutes. Cut the reserved

3 cloves of garlic into very thin slices. In a small skillet h eat the remaining

2 tablespoons oil and cook the sliced garlic until golden. Tr ansfer garlic chips to paper towels to drain.