I just did both in one day on Tuesday of this week. We had a FP for FoP and some time to kill, so we hung out in Nomad, then rode FoP, then ate late lunch at Satu'li. I'd happily recommend either, but Satu'li is my favorite place to eat in the whole of WDW because if how I choose to eat, Satu'li makes it easy, healthy, and offers variety. At Nomad there are a lot of Cocktails and Mocktails, small plates, and we were also told we could order off of Tiffins' appetizer menu or enhancements menu (those are Tiffins' side dishes).
I don't think you'd be disappointed in either choice.