I have a recipe for a lattice-topped rhubarb tart in which beaten egg whites
are incorporated into the rhubarb filling. The result is that they rise
through the lattice like a little meringue, making a very pretty
presentation.

I would suggest that as a dessert instead of a trifle, which seems too much
of a creamy thing to follow chicken and dumplings. (Although I like a good
trifle, I personally prefer fruit desserts that are at least slightly tart.)

And it would seem to me to be a better way to use rhubarb in this menu. The
rhubarb/butternut combo sounds like glop, to me. The sweet and sour Wolfert
recipe someone else suggested sounds much better.

I'm not a radish fan, so I can't comment on that course.