Heat the oil over medium heat in a large pot or Dutch oven. Add the onion and cook, stirring often, until translucent, about 5 minutes. Add the garlic, cumin, chili powder, salt and pepper, and cook, stirring constantly, until fragrant, about 1 minute. Stir in the pumpkin puree.

Add the beans, hominy, and broth to the pot and stir until well combined with the spice and onion mixture. Bring stew to a boil, then turn down the heat to low and cover the pot. Simmer until the beans and hominy are tender and broth has thickened slightly, about 40 minutes. Serve hot with desired garnishes, chips, tortillas, or flat bread.