In a medium bowl, whisk together the pineapple juice from the can, soy sauce, honey, tomato paste, grated garlic, and pepper. Pour the sauce over the pork tenderloin.
Add all but 1 cup (165 g) of the pineapple chunks into the slow cooker and reserve the remainder for the pico de gallo.
Cover and cook on high for 4 hours or on low for 8 to 10 hours. In the last hour, shred the pork with two forks and toss it in the sauce. Cover and continue cooking for the last hour.
Make the pineapple salsa:
In a medium bowl, combine Pico de Gallo with reserved pineapple chunks.
Serve:
Assemble pork tacos by layering some pulled pork on each tortilla and topping with pineapple pico de gallo, goat cheese, and cilantro.