Combine first 6 ingredients in a Dutch oven. Bring to a boil; cover, reduce heat, and simmer 35 to 40 minutes or until lentils are tender. Stir in salt. Transfer 2 cups lentil mixture to container of an electric blender; cover and process until pureed. Stir pureed mixture into remaining lentil mixture.
To serve, ladle soup into individual bowls and top each serving with a Cheese Biscuit.