Spray counter lightly with non-stick cooking spray. Combine dinner rolls or Texas rolls together and roll into an 11x17-inch rectangle. Place on a sprayed 11x17-inch baking pan, building up edges slightly. Poke several times with a fork and pre-bake at 350°F for 10-15 minutes. Remove from oven to cool.
In a small skillet, bring juice drained from pineapple to a low boil. Boil until reduced to about 2 tablespoons. Melt the butter into the juice. Add the sugar and stir until dissolved. Slice the onion into thin slices. Add to the pineapple mixture and saute, stirring frequently, until the onions begin to turn golden. Remove from heat and set aside.
Spread the prebaked crust with the pork. Sprinkle evenly with the cheese, sauted onions and pineapple.
Bake at 350°F for 15-20 minutes or until cheese is nicely melted.