Pork is pretty heavy, I'd usually pair it with something on the lighter side. Not saying potatoes won't be good, just might be a bit much. Have you ever tried this?:
Creamy Mashed Cauliflower Recipe | Eating Well
If I ate pork, still wanted something creamy/rich to go with it, this is what I'd recommend. This is literally the first recipe I found, you can spin however. Also, some things that go good with pork: Fennel, mustard, apples, peaches, melons. Some kind of fennel/cabbage/apple slaw with a slightly spicy and fruity sweet/sour vinaigrette would be the bee's knees, man.