Preheat the Dutch oven to 350 degrees F (175 degrees C).
Prepare the pork by partly cutting slices into the ham. Each cut is the same width as a slice of pineapple and stops about 1/2-inch (1 1/2cm) above the base in a Hassleback style.
Open the can of pineapple and remove the pineapple rings while saving the juice. Cut each pineapple ring in half.
Carefully put each half of pineapple into the slices in the ham, until all the cuts have been filled.
Place the stuffed ham in the preheated Dutch oven. Pour the reserved pineapple juice over the ham, then sprinkle with the pork rub.
Set the Dutch oven to cook at 350 degrees F ( 175 degrees C) and roast the ham for 45 minutes.
After 45 minutes check the ham and pineapple. You are looking for color on the top and bottom of the ham and the ham to be warmed through.