Imperial Lamb Barbacoa with Ancho Chile 'Drunken' Sauce and Purple Sweet Potato Silk

Prepare the Lamb Barbacoa: In a blender, combine white vinegar, 6 garlic cloves, 1/2 chopped white onion, cumin, oregano, black peppercorns, bay leaves, avocado leaves (if using), and 2 tablespoons of salt. Blend until a smooth paste forms.

Pat the lamb shoulder dry. Generously rub the spice paste all over the lamb, ensuring it's thoroughly coated. Place the lamb in a large bowl, cover, and refrigerate for at least 4 hours, or preferably overnight.

Preheat oven to 160°C (325°F). Line a large Dutch oven or a deep roasting pan with the softened banana leaves, ensuring they overlap and extend beyond the edges of the pan. Place the marinated lamb shoulder inside the banana leaves. Pour 2 cups of beef broth into the bottom of the pan.

Fold the banana leaves over the lamb to completely enclose it. If using a roasting pan, cover tightly with a layer of parchment paper, then a double layer of aluminum foil to create a tight seal. This mimics the traditional pit cooking method, trapping moisture.

Braise the lamb in the preheated oven for 4 to 5 hours, or until the lamb is fork-tender and easily pulls apart.

While the lamb is braising, prepare the Ancho Chile 'Drunken' Sauce: Heat a dry skillet over medium heat. Toast the dried ancho and guajillo chilies for 1-2 minutes per side until fragrant, being careful not to burn them. Transfer to a heatproof bowl, cover with hot water, and let them rehydrate for 20-30 minutes until soft.

In the same skillet, dry roast the tomatillos, 3 garlic cloves, and 1/4 chopped white onion until softened and slightly charred.

Drain the rehydrated chilies. In a blender, combine the softened chilies, roasted tomatillos, garlic, onion, Mexican lager beer, chicken broth, piloncillo (or brown sugar), and apple cider vinegar. Blend until very smooth. If needed, add a little more chicken broth to achieve a pourable consistency.

Heat 2 tablespoons of vegetable oil in a saucepan over medium heat. Pour the blended sauce through a fine-mesh sieve into the saucepan, pressing on the solids to extract all liquid. Discard the solids.

Bring the sauce to a simmer, then reduce heat to low and cook for 15-20 minutes, stirring occasionally, until it thickens slightly and the flavors meld. Season with salt to taste. Keep warm.

Prepare the Purple Sweet Potato Silk: While the lamb finishes cooking, place the diced purple sweet potatoes in a pot and cover with cold water. Bring to a boil and cook until very tender, about 15-20 minutes. Drain thoroughly.

Return the drained sweet potatoes to the pot. Add butter, heavy cream, salt, and white pepper. Mash with a potato masher or pass through a food mill for an extra smooth consistency. Alternatively, use an immersion blender or stand mixer on low speed until silken smooth. Keep warm.

Once the lamb is cooked, carefully remove it from the oven. Discard the banana leaves and any large bone pieces. Using two forks, shred the lamb into large, tender pieces.

To serve, spoon a generous amount of the purple sweet potato silk onto plates. Top with the shredded barbacoa lamb. Ladle the warm Ancho Chile 'Drunken' Sauce over the lamb. Garnish with fresh chopped cilantro and thinly sliced radishes. Serve immediately.