In a large mixing bowl, combine the coconut yogurt, milk, egg, and salt, and whisk together until well combined.
Slowly pour 1/3 of the flour into the liquid mixture, mixing constantly to combine well. Repeat for the second 1/3, and then the last. I like to get my hands in there to help combine the last of it really well as it will be thick and sticky at this point.
Prepare a clean surface on your counter, lightly dusted with more of the gluten-free flour blend. Place the dough on the floured surface, and with floured hands knead the dough until it becomes easier to handle and less sticky.
Form a ball. Put it back in the bowl and cover with plastic. Allow it to rest. I put mine in the fridge overnight but this isn't necessary.
While it rests, prepare the appropriate filling (see recipe below).
Enjoy savory pierogies with a dollop of unsweetened coconut yogurt, and/or sauteed onions. If you've used a sweet filing, you could eat them will a scoop of vanilla coconut yogurt, drizzled chocolate sauce, or sprinkle icing sugar on-top.