For the salsa, put the onion, garlic and tomatoes on an oiled baking sheet and roast them in the oven until the skins of the tomatoes are blistered and the onions are lightly browned and soft, 15-20 minutes. Remove and let cool.

Toast and rehydrate the chiles in about 4 cups of water (see directions below). Reserve the rehydrating liquid. In the jar of an electric blender, combine the roasted vegetables with the chiles, 2 cups of the rehydrating liquid, salt and pepper. Purée until smooth. Set aside.

Season the short ribs on all sides with salt and pepper. Heat a large, oven-safe pan on high heat. Add the canola oil and sear the short ribs on all sides until browned, about 2 minutes per side. Stir in the salsa and simmer for 5 minutes. Add 4 cups of the chicken stock, the oregano, the bay leaf and season to taste with salt and pepper. Bring the liquid to a boil, cover the pot, and transfer to the oven for 1 1/2 hours, or until the meat is very tender, adding more stock if needed to cover the meat.

Remove the short ribs from the cooking liquid and strain the broth into a clean pot. Bring to a boil and reduce by a third, skimming to remove the fat from the surface. Return the ribs to the broth and keep warm.

To Serve:
Toss the cabbage with the lime juice and season to taste with salt. Put 2-3 short ribs in a bowl. Ladle 1 cup of the broth over the meat, garnish with 1/4 cup cabbage and a sprinkle of cheese.

Serve with warm tortillas and roasted garlic mashed potatoes.