Depends on their size of course, but just think of them as a form of puff-pastry tartlet crusts and/or shells and the world's your oyster. You're having trouble thinking of the "right" thing not because there aren't many good choices, but because there are too many. Loosen up and let your fancy fly.
I'm always tempted to fill them with one or another sort of mousse or souffle. Or, how about a galantine of artichoke?
You could use them as shells and fill them loosely with whatever -- say a coconut/corn chutney if that suits.
We all have a tendency to freeze up when confronted by a lot of good choices, trying to figure out which is the best among them. The secret is there's no one best. In this case, anything which tickles you, can easily be made to work.
Let your inner maker of mud pies enjoy herself,
BDL