Crispy shallots also complement those types of purees well - just slice a bunch of shallots thin and saute them in oil/butter until very brown and crispy, and drain on paper towel. They keep well in the fridge, so you can do them ahead too.

Chestnuts are such a delicate flavor, so perhaps almonds? Or chopped roasted chestnuts?

hazelnuts might work nicely too.

How about some shaved parmesan, crisped in the oven. Wait, even better, aged gauda...

How about chopped toasted walnuts? Or one of AntoniaJames' nut recipes on the site? Like this one: http://food52.com/recipes/7334_crispy_spicebrined_pecans