Tortillas with Grilled Adobo Pork and Pineapple

Remove stems, seeds, and membranes from chiles, then break into large pieces and set aside. In 4-quart saucepan over moderate heat, heat oil until hot but not smoking. Add onion, garlic, cloves, cinnamon, peppercorns, and cumin seeds and cook until onion is soft and golden brown, about 6 minutes. Add chilies and cook until darkened on both sides, about 1 minute. Add enough water to cover mixture halfway and bring to boil. Continue boiling until liquid reduces by half, about 5 to 8 minutes. Transfer mixture to blender and purée until smooth. Strain, pressing on solids with rubber spatula and discarding solids.