In a large saucepan, combine the chicken broth, 6 cups of water, 1 small onion, bay leaf, parsley and thyme. Bring to a boil, then reduce heat to low and simmer for about 1 1/2 hours. Strain, and reserve 4 cups of the broth for the recipe. Reserve the remaining broth for other uses.
Pour the 4 cups of broth into a large soup pot, and add 4 cups of water to it. Stir in lentils, and bring to a boil. Cover, reduce heat to low, and simmer for about 1 hour.
Heat olive oil in a large skillet over medium heat. Add the large onion, and cook until transparent, stirring frequently. Add the garlic, and cook for just a minute, until fragrant. Place the chard in the pan, and cook until wilted, about 5 minutes. The smells here are delicious!
Transfer the chard and onion mixture to the pot with the lentils. Stir in the cilantro and lemon juice. Season with salt and additional lemon if desired. Simmer covered for an additional 15 minutes before serving. Serve with lemon wedges.