In a large skillet, add a thin layer of vegetable oil just to coat. Heat the oil over medium heat.
Cooking in 1 pound batches, add al pastor to the hot oil and cook for 5 minutes, stirring often to prevent the sauce from burning.
Add half the pineapple and continue to cook until the liquid evaporates and the al pastor crisps up. You will need to stir more often as the liquid evaporates to prevent burning.
If the sauce starts to burn before the al pastor crisps up, you can finish the process under the broiler. For easy clean up, line a large baking sheet with foil and spread the pork out in a single layer. Broil until crispy.
Repeat for the second batch of al pastor.
Al pastor can be used in whatever Mexican dish that you like including tacos, burritos, and quesadillas.