Place a Dutch oven or large soup pot over medium-low heat. Add coriander seeds and toast, shaking the pan frequently, for 2–3 minutes until they’re aromatic and lightly browned. Transfer the seeds to a spice grinder or mortar and grind to a fine powder.

In the same pot, add vegetable or olive oil, ground beef (if using), onion, and garlic. Cook for about 4 minutes, stirring frequently, until the beef is browned and the onion is softened.

Pour in 4 cups of stock along with the chopped green chile and ½ tsp ground coriander. Bring to a gentle simmer, letting the flavors meld for 15 minutes. If the stew seems too thick, add more stock to your liking.

Stir in the cooked pinto beans and let the stew simmer for an additional 10 minutes, allowing the beans to absorb the flavors of the broth. Taste and adjust seasoning with salt if needed.

Ladle the stew into bowls and top each portion with grated cheese and minced onion if desired. Serve hot with warm flour tortillas, corn tortillas, or a slice of cornbread to soak up the rich broth.