Preparation

For the tomato sauce

Roughly chop chiles and set aside. In a large saucepan, heat oil over medium-high heat. Add onion and garlic, and season to taste with salt. Cook, stirring occasionally, until garlic just starts to turn golden. Add chiles, and stir to coat in oil. Add broth and tomatoes, and bring to a boil. Reduce heat and cook on a low simmer until chiles are tender, about 15 minutes. Remove from heat and let cool slightly.

Once cooled, transfer to a blender, and blend until smooth. Return to the pot, and bring to a simmer. Season to taste with salt. Add cilantro and spinach, and stir until spinach is wilted. Cover and keep warm while you make the meatballs.

For the meatballs

In a large frying pan, heat 2 Tbs. of the olive oil over medium-high heat. Add onion and cook, stirring occasionally, until onion is translucent. Add mushrooms, and stir to coat in the oil. Cook undisturbed until mushrooms are golden on the bottom. Add garlic, and continue to cook until garlic just begins to turn golden. Remove from heat and let cool slightly.

In a food processor, combine chickpeas, salt, oregano, chipotle, cumin, and cilantro. Pulse a few times until ground but not pureed. Add mushroom mixture, and pulse a few times to combine. (You want the mixture to be minced but still have some texture.)

Transfer mixture to a large bowl. Add bread crumbs and egg, and mix to combine. Scoop walnut-size balls of the mushroom mixture onto a baking sheet, then roll into smooth balls with your hands. (Wet your hands to prevent the mixture from sticking. If mixture is too dry to stick together, add a little water.) Chill meatballs for 15 minutes.

In the large frying pan, heat the remaining 4 Tbs. olive oil over medium-high heat. Cook meatballs in batches—don’t overcrowd the pan—until browned on all sides.

Serve meatballs with the guajillo-tomato sauce.