In a large pot place tomatillos, onion, garlic, cilantro, and water. Cover and simmer until tomatillos are fully cooked, they must be light green and very soft.
With a food processor or blender, blend the vegetables with salt.
Return to the pot and add the chickpeas and serrano chile. Simmer and taste, if the broth is to thick add about a cup of water and try again,add water slowly until you have the right consistency.
Serve in a bowl and top with shredded lettuce, cilantro, oregano, radish, avocado, pumpkin seeds, and chips.