In a small bowl, combine pineapple juice, vinegar, brown sugar, curry power, and kief or hash. Stir to combine and set aside.
Heat oil over medium heat in a large sauté pan. Add crushed red pepper and cook, stirring, for 30 seconds. Add the onions and cook, stirring, until soft, about 2 minutes. Stir in the ginger and Serrano pepper, and mangos and cook, stirring, for another minute. Add the mixture from the bowl and stir to combine. Bring to a bar simmer, cover and cook, stirring occasionally, for 15 minutes. Stir in raisins and remove from heat.