Adapted from here.
1 tablespoon olive oil
4 leeks, white and light green parts, sliced
4 garlic cloves, chopped
4 potatoes, peeled and cubed
2 vegetable bullion cubes
5 cups of water
1 (14 ounce) can white beans, drained
1 teaspoon fresh rosemary
salt and pepper
Heat olive oil in a 4-quart pot. Sauté the sliced leeks about 5 minutes or until slightly tender. Add garlic and sauté another minute or so. Add potatoes, vegetable bullion cubes, and water. Bring to a boil. Reduce heat to medium and simmer until potatoes and leeks are quite tender. Add beans, rosemary, salt, and pepper, and more water, if necessary.
Put in food processor in batches and puree until smooth. If necessary, return to heat until warm enough.
For variation: Put a little sour cream, bacon bits, or sprinkle with soy cheese.
Use for later: Freeze the left over leek greens and use them in vegetable stocks.