Step 1

Put the tomatoes, onion and garlic on a baking sheet lined with foil. Place under the broiler for about 10 minutes until charred, mushy, and soft, flipping once halfway through. Remove from the oven and once cool enough to handle, peel the garlic cloves. (Alternatively, you can char and toast on a preheated comal or skillet set over medium-low heat.)

Step 2

Place tomatoes, peeled garlic and onion in the jar of a blender.

Step 3

Toast the guajillo and ancho chiles on a heated comal or skillet for about a minute, flipping a few times, until lightly browned and fragrant. Place the chiles in a medium saucepan, cover with water, and simmer about 10 minutes until soft and rehydrated.

Step 4

Transfer the rehydrated chiles, along with 1 cup of their cooking liquid, to the blender with the other ingredients. Add in the orange juice, vinegar, piloncillo, marjoram, thyme, oregano, salt, and pepper and puree until completely smooth. Let cool.

Step 5

Preheat the oven to 325°F with the rack set in the bottom third.

Step 6

With a small paring knife, pierce the pork butt all over so it will absorb the marinade. Place it in a large oven-proof casserole or baking dish and cover with the marinade* and add the bay leaves. Cover with a tight fitting lid or aluminum foil.

Step 7

Place in the oven and roast for 3 hours or until meat is completely tender. Remove from the oven and raise the temperature to 375°Carefully remove the lid or foil, baste the sauce all over the meat and return to the oven, continue cooking another 20 to 30 minutes until browned on top.

Step 8

Transfer the meat to a chopping board and let rest. Meanwhile cook the sauce in the casserole over medium-high heat or until thickened to a gravy consistency, about 15 to 20 minutes. Slice the meat, coarsely chop if desired, and place on a platter and dress with the sauce.

Step 9

*Note: You can marinate the meat for up to 48 hours or roast right away.