Preheat your oven to 350°F.
Line a 9"x13"x2" baking tray with half of the Ti-leaves, using 2-3 pieces depending on size. Let the leaves stick out slightly from the pan. Lay half of the luau leaves on top of the Ti-leaves in the tray.
In a large mixing bowl, combine the cut short rib, pork belly, and sweet potato. Add the shoyu, Hawaiian salt, liquid smoke, and baking soda. Mix everything together until evenly coated.
Evenly distribute the meat mixture over the luau leaves in the tray. Add in 1 to 2 cups of water then cover the meat with the remaining luau leaves, tucking the edges into the pan. If the leaves are large, you can cut them in half.
Cover the luau leaves with the remaining Ti-leaves, arranging them neatly over the top. Tightly cover the entire tray with aluminum foil.
Bake the pan laulau for 2 ½ to 3 hours, until the luau leaves are thoroughly cooked and tender. This ensures the calcium oxalate in the leaves breaks down
Once done, leave the laulau covered and let it rest for 20 minutes to allow the luau leaves to continue steaming.
Once the pan laulau has finished cooking, carefully remove it from the oven. Peel back the aluminum foil and Ti-leaves.
Garnish the pan laulau with the lomi tomato and additional chopped green onions if desired. Serve hot and enjoy!