Whisk the pork belly sauce ingredients together. Divide in half and set half of it in a container for later. Pour the other half of the marinade into a ziplock bag then add pork belly, cover and place in the fridge overnight.
The next day, remove pork belly from the marinade (discard marinade) and pay dry. Preheat oven to 450 degrees F. Line a baking sheet with foil and place a wire rack on top. Place pork belly fat side up on the wire rack. Put in the oven to bake for 30 minutes then turn oven down to 225 degrees F and cook for 1 hour. (1 hour per pound of pork belly) Once cooked, remove and let rest for 5-10 minutes before slicing into small bite size pieces.
When the pork belly has about 15 minutes left in the oven, prepare the pineapple salsa. Add all ingredients in a bowl to combine and set aside.
Lastly, using the marinade that you placed in a container the night before, pour it into a large skillet over medium heat. Bring to boil and let reduce until the mixture thickens and coats the back of a spoon, about 8-10 minutes. Once thickened, toss pork belly in the sauce.
Heat tortillas over an open flame on our stovetop or in a pan, then add pork belly, pineapple salsa, and srirachamayo on top of all of it! Then eat and cry tears of joy!