MAKE THE CHORIZO: In a small skillet over medium heat, toast the peppercorns, allspice, and cloves, swirling the pan often, until very fragrant, for about 1½ minutes. Add the cumin seeds and cook until the cumin smells earthy and fragrant, for about 30 seconds. Set aside. In a large saucepan, cover the chiles guajillos and chiles anchos with water. Bring to a boil. Cover the pot, remove from the heat, and let sit until the chiles have softened, for about 30 minutes. Drain and discardthe liquid. Transfer the chiles to a blender. Add the toasted spices, the vinegar, garlic, oregano, salt, thyme, and canela and puree until smooth. Transfer to a large bowl. Add one-quarter of the pork to the bowl and mix together (combining just a small amount of meat in the beginning makes it easier to incorporate the rest without overmixing). Add the remaining pork and mix well to thoroughly combine, but don’t overwork it or it will gettough and sticky. Cover the bowl tightly with plastic wrap and refrigerate for at least 24 hours and up to 4 days. (I like to marinate the mixture for 4 days for maximum flavor.) After it’s marinated, you can use half of it (1 pound) right away to make these tlayudas or any other recipe that calls for fresh chorizo. And you will still have another pound to freeze for later! Divide the chorizo in half and place one half (a little over 1 pound or ½ kilo) in a freezerbag and freeze for up to 3 months. MAKE THE TLAYUDAS : (You will only be using 1 pound of the chorizo for the tlayudas.) In a large skillet, preferably cast-iron, over medium-high heat, heat 2 tablespoons of the lard until hot. Cook half of the chorizo, breaking it up with a wooden spoon and stirring often, until browned and cooked through, for 7 to 9 minutes. Transfer the chorizo to a plate and repeat with another 2 tablespoons of the lard and the remaining meat. Arrange a rack in the center of the oven and preheat to 475°F. Brush one side of each of the tlayudas with the remaining 2 tablespoons lard. Place on a sheet tray and bake until just beginning to brown, for about 5 minutes. Remove from the oven and carefully spread a thin layer of frijoles on top of each tlayuda. Sprinkle with the chorizo, queso Oaxaca, queso fresco, and sliced jalapeño en escabeche (including carrot and onions). Serve with the salsa de aguacate. I like to drizzle with the jalapeño brine from the escabeche instead of a squeeze of lime! COOK’ S NOTE : Ideally, when you make sausage, you want 25 percent of the weight of the meat to be fat. It’s difficult—if not impossible—to find 75/25 pork in the supermarket. But if you ask your butcher at the meat counter nicely, he or she will be more than happy to take some of the trimmings in the back and grind them into your pork. If not, you can mix in ½ cup cold lard into the pork and spice mixture, and this will add more flavor and a bit of richness to leaner ground pork.