First the filling:
Peeled potatoes set to boil and yellow onions sauteing in olive oil with salt and black pepper.

The onions need to cook on medium low for a while, until they're really dark and sweet.

Potatoes drained, mashed and mixed with onions and a little garlic powder - to taste.

Set aside and onto the batter.
The batter was 3 large eggs, pinch of salt, 3/4 C. potato starch and approximately 1 1/4 cups of water.

It should be very loose and well combined:

You can't tell if the batter is too thick until you make your first crepe. If it's too thick add some more water. If it's too thin, you can add a little potato starch.

Lightly grease a non-stick pan, heat over medium/medium low and pour in enough batter (a 2oz. ladle works well) to form a thin crepe (a small pan would work much better, but slim pickings at home). Pour out any excess batter:

Cook until the top of the crepe is dry, but the bottom hasn't browned. Turn over onto a lined tray:

Continue until all the batter is used - layering between sheets of wax or parchment paper. Makes about 12.

Place the crepe onto a work surface so that the side that was up in the frying pan is down on the work surface. Form the filling into a long, narrow shape and place on one end of a crepe :

Roll over once, then fold in each side:

Continue to roll the blitz up and finish all of them:

Before serving, finish the blintzes by browning them in a non-stick pan. I used oil here, but for a dairy meal they're great in butter.