Char the pineapple and onion on the grill or under the broiler. Allowed to cool.
Mix the oil, aji amarillo, and adobo seasoning in a cold sauté pan to make a paste. Warm over medium heat until the mixture darkens slightly and becomes fragrant, taking care not to burn the spices.
Puree the pineapple, onion and garlic along with the lime juice and cilantro. Add cooled spice paste and continue to puree to a chunky consistency. Stir in salt to taste.
Excellent served with chips, or as a condiment for grilled fish or meats.