2 whole — ripe mangoes, peeled and diced • 1/2 small red onion, finely chopped • 1–2 tbsp fresh ginger, grated • 1 garlic clove, minced • 1/2 tsp mustard seeds • 1/2 tsp cumin seeds • 1/4 tsp chili flakes (or to taste) • 1/2 tsp salt, or to taste • 1/3 cup apple cider vinegar (or white vinegar) • 1/4 cup brown sugar or maple syrup • 1/4 cup raisins (optional, for sweetness and texture)