Preheat oven to 475 degrees F.
Pat pineapple slices with a few paper towels to remove as much juice from them as you can. The pineapple will release a lot of liquid while cooking so make sure to dry them out as much as you can before putting into the pork mixture.
In a large bowl mix ground pork with 1/4 cup of reserved pineapple-chili sauce, garlic, cilantro, diced pineapple, and salt.
Oil hands, and form pork mixture into balls that are about 1 inch in diameter. Place in a deep oven safe dish.
Place in oven for 10 minutes until meatballs have lightly browned on the outside.
Remove from oven and carefully drain excess liquid.
Pour the rest of the pineapple-chili sauce over the meatballs, and top with canned pineapple slices if desired.
Cook 12-15 minutes longer until pork is cooked through and no longer pink in the middle.
If pineapple has not browned you may set the oven on broil for the last few minutes of cook time.
Garnish with crumbled cotija cheese or queso fresco, and serve with tortillas or rice.