In a saute pan over medium heat add the coconut oil, heat for a minute then add the onion and pineapple, cook until starting to carmelize, about 10 min. Cool completely.
While the pineapple mixture is cooling make the taro chips. Spread the taro rounds onto baking sheets lined with either parchment or silicone baking mats. Brush both sides of the slices with coconut oil and sprinkle with the salts. Bake at 400 Deg for 15-20 min. Checking half way and flipping some chips if needed. Remove when starting to turn golden brown. The thicker pieces will take longer to bake. Transfer to a bowl and sprinkle with more salt if desired.
Once the pineapple onion mixture is cool add it to the ground pork in a large mixing bowl along with two teaspoons of the guava garlic salt and mix. Form into four patties about 1 inch thick and about 5 inches across. Sprinkle the remaining salt over the top. They will be thick patties.
Grill on medium high heat on a preheated grill for about 10-12 minutes, flipping once halfway through cooking. Grill the pineapple for a few min while the burgers are grilling.
Let the burgers rest while you assemble the rest of the ingredients.
Slightly toast the buns, spread mustard on the bottom, layer with lettuce, tomato slices, the burger patty then a grilled pineapple slice. Spread some of the guava ketchup on top and then add the top bun. Serve with taro chips and an ice cold beer. Preferably Maui Brewing Co Mana Wheat. Its brewed with pineapple!!!