Position broiler rack 6 inches (15 cm) from heat source. Broil ribs on both sides, until lightly browned, about 7 minutes per side. Drain on paper towels and transfer to stoneware.
In a skillet, heat oil over medium heat for 30 seconds. Add onions and cook, stirring, until softened, about 3 minutes. Add garlic, oregano, cinnamon stick, salt, peppercorns and allspice and cook, stirring, for 1 minute. Add apples, tomatoes with juice and 1⁄2 cup (125 mL) of the chicken stock and bring to a boil.
Pour sauce over ribs. Cover and cook on Low for 6 hours or on High for 3 hours, until ribs are tender and falling off the bone.
Half an hour before recipe has finished cooking, in a heatproof bowl, soak ancho chiles in boiling water for 30 minutes, weighing down with a cup to ensure they remain submerged. Drain, discarding soaking liquid and stems and chop coarsely. Transfer to a blender. Add jalapeño, bananas, vinegar and remaining 1⁄2 cup (125 mL) of the chicken stock. Purée.
Add puréed chiles to stoneware, along with pineapple and stir well. Cover and Cook for 30 minutes, until hot and bubbly and flavors meld. Discard allspice and cinnamon stick.
Notes: Works best in a large (minimum 5 quart) slow cooker.