lentil soup w/ sweet potatoes & Shiitake mushrooms

1 tbsp extra virgin olive oil
1 leek, thinly sliced (white part only)
2 cups sliced shiitake mushrooms
6 cloves garlic, minced
4 cups chicken or vegetable broth
2 cups water
1 1/2 cups lentils
1 large sweet potato, scrubbed and diced
1 bay leaf
1/4 c. basil

In a large saucepan, heat olive oil and saute leek, mushrooms, and garlic for 3-4 minutes until leek is soft. Stir in broth, water, lentils, sweet potato and bay leaf. Simmer uncovered until lentils and potatoes are tender, about 30-40 minutes. Remove bay leaf, and stir in basil. If soup seems think, thin with water until desired consistency. Season with pepper and salt (if desired), and serve hot.

about 4 servings.