Combine all the other ingredients into a bowl and stir until the sugar is mostly dissolved. Put this mixture in a sauté pan and cook on medium-low heat just until the mixture starts to bubble a little. At this point, it's done. If you cook too much, it will turn into rock-hard delicious candy and will be impossible to apply to the pineapple...though it may be good to nibble on afterwards.

Apply your juicy-goodness-sauce to the pineapple slices. Make sure your grill is nice and hot, and place the pieces on the grill. As the pineapple cooks, add more of the sauce - kind of like a progressive basting process.