Peel the apples and cut into quarters. Roughly chop in the work bowl of a food processor fitted with the steel blade.
Heat the oil in a large saucepan or frying pan over high heat. Add the mustard seeds, immediately cover (to avoid splashing all over your stove), and cook until the popping stops. Immediately remove the pan from the heat so that the seeds don't burn. Then, reduce the heat to medium high, and add the onion, red pepper, and salt. Cook, uncovered, stirring, until the onions are translucent. Stir in the garlic, chile, ginger, and allspice. Cook 1 minute.
Add the remaining ingredients, including the prepared apples. Cook, uncovered, over medium heat, until soft and aromatic, about 25-30 minutes. Either serve hot or cold, with rice and Potato Pea Curry.