Step 1Coat 5-quart saucepan with nonstick spray. Add olive oil and heat until hot. Add leek, onion, garlic and carrot and saute until tender over medium heat, about 5 minutes. Add mushrooms and 1/2 cup broth. Bring to simmer, then cover and cook mushrooms about 5 minutes.
Step 2Stir in lentils and remaining broth. Bring to boil. Reduce heat, cover and simmer until lentils are tender, about 35 minutes. Stir in Swiss chard. Simmer 2 to 3 minutes. Add salt and pepper to taste.