What’s an unsweetened desert of this January? Thank you.

This salted rosemary shortbread might be nice https://food52.com/recipes/82215-salted-rosemary-shortbread It has a touch of sugar in it, but definitely skews savory, from reading the recipe. ;o)

We have a friend who serves really good vanilla ice cream in a pool of mango puree. It’s not terribly sweet & it’s pretty.

Not entirely sure if this qualifies, but how about Bosc or d'Anjou pear slices served with Brie or Camembert, or Bartlett pears served with Halloumi? That's my go-to when I don't want a sweet dessert. ;o)

A dessert, by definition, is the sweet course of a meal. If you don't want a sweet course, you can finish a meal with a salad or cheese course. You could exclude dessert altogether.

You could consider a cheese plate, often served after dinner with a selection of different textured / flavored cheeses and perhaps some fruit

I don’t understand your question. Are you looking for desserts made without added sugar?