Dice the Spam, fresh pineapple, and red bell pepper to a uniform size (about the size of a pea).
Of course you will need to clean and core the pineapple. I like to use a pineapple tool. Also, try to reserve some of the pineapple juice to use in the sauce. While fresh pineapple is ideal for the most elevated flavor, alternatively, you can use a can (15 ounces) of pineapple chunks.(diced). If you do this, you will have plenty of juice for the sauce.