Preheat oven to 300°F.
Using small knife, cut 1/4-inch-deep slits 1 inch apart all over pork roast.
Rub 2 tablespoons of sea salt all over pork. Unfold 1 banana leaf on work surface and place pork roast on top of banana leaf.
Fold up leaf around pork, enclosing completely. Repeat wrapping pork in remaining banana leaves, 1 at a time. Tie with kitchen string to secure, then wrap roast in foil. Place pork in roasting pan; pour 4 cups water into pan.
Roast pork in oven until very tender when pierced with fork, about 4 hours. Unwrap pork and cool slightly.
Shred pork with forks and place in large bowl.
Bring remaining 2 cups water and remaining tablespoon of salt to a boil in small saucepan. Add liquid smoke; pour over pork and stir to blend. Let stand 10- 15 minutes to allow liquid to flavor pork.
Combine mustard with pineapple juice and soy sauce in a small bowl
Slice open and butter the outsides of KING'S HAWAIIAN Sweet Rolls top and bottom. Slice 4 slices of spam length wise about ¼ in thick, then cut in half.
Sear spam in a frying pan on med heat with a little oil aprox. 30 sec. on each side.
Place about 2 oz. of kalua pork on each roll. Top pork with seared spam, then cheese, then pickles. Spread mustard on the inside of top portion of roll and place on top of slider.
Heat a large frying pan on low heat for about 2 minutes.
Cook sliders in frying pan with brick or alternate pan on top to smash down while cooking. Cook for 2 min or until golden brown. Flip slider over and cook for another 2 minutes weighed down or until sliders are toasted on both sides.