In a large enameled cast-iron casserole, heat the remaining 1/4 cup vegetable oil. Season the lamb shanks with salt and pepper. Add them to the casserole and brown over moderately high heat, about 4 minutes on each side; transfer to a platter. Add the coarsely chopped onion, garlic, carrots, tomato paste, the remaining spice mixture and 3 tablespoons of the chile-almond paste and cook, stirring, until fragrant, about 3 minutes. Stir in the stock and wine and add the shanks.