Again, this just happens to be vegan. But maybe you just want a handheld potato salad*, and that's ok too!
Fingerling potatoes (the idea is they'll look like eggs when halved), I like multicolor
Vinegar and pickles of some kind (like a partial jar of pickles and their juice)
Nooch (nutritional yeast or vegan mayo to make the filling creamy) or pesto or both
Finishing salt or paprika, maybe some edible flowers
Following is based on about 20 halves because that's what my deviled egg plate fits:
Halve your fingerlings and boil until somewhat soft (you should be able to insert a fork smoothly into the middle but skin should be intact). To cool down the potatoes, cover them with some pickle juice (I used ramps and their vinegar in the demo) and refrigerate for a few hours or overnight. I put mine in a Ziploc.
Once they're chilled use a truly round measuring spoon (or you could get fancy with an actual melon baller, I suppose) depending on the size of your tater (hee hee) to make a depression in the half just like an egg white would have and to get the middle for the filling.
Mix the filling with a little of the pickle juice/vinegar, maybe a tablespoon. I used about 1 Tbsp of the nutritional yeast and 1 Tbsp ramp pesto, salt & pepper. You can finely finely chop some of the pickles but I pipe mine (from the same Ziploc bag I use for brining) so keep that in mind. You could also use like a slice of cornichon on top of the finished product (like my Mama did with slices of stuffed Spanish olives).
Once you've adjusted the filling to be creamy, you can spoon it into the Ziploc bag, cut off the tip, and voila you have a piping bag! I find that's easier and less messy than trying to spoon filling into real or fake half-eggs.
Sprinkle with paprika or finishing salt and/or a garnish of some sort.
*Note to self - slightly larger potatoes and this very thing; like a chilled potato skin with tater salad. . .