11. Remove stems and seeds from chile ancho, chile guajillo, and chile pasilla. Toast the chiles lightly in a dry comal or skillet until fragrant, being careful not to burn them. Place the toasted chiles in a bowl and cover with 500 grams of hot agua. Let them rehydrate for 20-30 minutes until softened.
22. In a blender, combine the rehydrated chile ancho, chile guajillo, and chile pasilla (reserving the soaking liquid), ajo, cebolla blanca, comino en grano, orégano mexicano seco, pimienta negra en grano, clavo de olor entero, hojas de laurel secas, vinagre de manzana, and 15 grams of sal de mar. Add 500 grams of fresh agua and blend until a smooth paste forms. If needed, add a small amount of the chile soaking liquid to achieve a smooth consistency.
33. Cut the borrego pierna y paleta into large, manageable pieces. Season the borrego generously with the remaining 10 grams of sal de mar. Spread the blended marinade all over the borrego, ensuring it is thoroughly coated. Cover and refrigerate for at least 4 hours, or preferably overnight.