In a molcajete (or bowl), grind together cumin, 2 cloves garlic, and 1 teaspoon salt until a paste forms. Add ground beef, egg, and chopped onion to this paste. Mix until evenly combined. Set aside.

Remove seeds from guajillo (and árbol, if using) chilies. Rinse. Heat water until hot (but not boiling). Remove from heat, add chilies, cover pot, and soak about 5 minutes until softened.

Boil Roma tomatoes until soft (about 5 minutes). In a blender, combine soaked chilies (with their soaking water), boiled tomatoes, leftover garlic (as desired), ¼ onion, bay leaves, and cloves. Blend until smooth to make the chili‑tomato sauce.

Shape the ground beef mixture into meatballs of your preferred size. Set them aside.

In a pot over medium heat, add oil. Add fideo noodles and sauté, stirring frequently, until they turn golden brown. Be careful not to burn.

Pour the chili‑tomato sauce into the pot with golden fideos. Let it simmer for ~5 minutes. Then gently add the meatballs. Bring to a gentle boil, reduce heat, cover, and simmer until meatballs are cooked through (about 15‑20 minutes). Add water as needed to adjust consistency. Adjust salt to taste.

Remove bay leaves. Serve hot, garnished with chopped fresh epazote (if using), extra onion or cilantro. Great with warm tortillas, rice, or a squeeze of lime.