Add the ginger, paprika, cumin, and black pepper to the pot and stir. Add the broth and the lentils, chickpeas, tomatoes, and potatoes. Bring to a boil, reduce heat, cover and simmer for 50 minutes, or until lentils are tender. Add lemon juice, chile paste (start with 1 tsp and add more to taste) and chard. Cook for 5-7 minutes more, until chard is tender. Season with a bit of salt, serve hot.