Heat oil in a large soup pot over medium-low heat. Add leeks, garlic, and celery and cook for 5 minutes or until leeks are clear. Add broth, water, bay leaves, lentils, and kombu and bring to a boil. Reduce heat and simmer, uncovered, for 20 minutes or until lentils are tender.

Add chard, lemon juice, and zest and cook 10 minutes more, or until chard is wilted. Before serving, remove bay leaves and kombu, stir in parsley, and season to taste with salt and pepper. Serve, garnished with lemon wedges.