Galettes de sarazin (sourdough) - Untested

Below are several recipes I need to read through for similarities, differences and interesting tips.

https://www.fermentingforfoodies.com/buckwheat-crepes/

SOURDOUGH FERMENT
1 cup buckwheat flour
2 cups water (chlorine free)
REMAINING INGREDIENTS
1 egg
2 tbsp melted butter
1/4 tsp salt
INSTRUCTIONS
Mix the flour and water in a glass container and leave it somewhere warm to ferment for 12-24 hours. Buckwheat is very quick to catch a sourdough starter, so it won’t take long before it starts to bubble.
When you are ready to make the crepes, add in the remaining ingredients and mix well.
Preheat a cast iron pan or non-stick pan on medium until it is hot.
Ladle on a small amount of batter. It should be liquidy enough to spread into a thin layer right away. However, you don’t want it too thin or it will be difficult to flip.
Once it has started to bubble and the middle of the crepe has begun to dry out, flip the crepe over and allow to cook for another minute on the other side.
Fill and serve immediately.
NOTES
Traditional crêpe pans are flat cast-iron circles with a long spatula (affiliate links.)  I just used my cast-iron frying pan and regular spatula, which worked with this recipe.
Light buckwheat flour is nice for crepes (like in my photographs.) However, dark buckwheat flour will give your crepes a beautiful purplish shade and an earthy flavour.
Traditional fillings for buckwheat include: cheese, bacon, sausages and scrambled eggs. Sweet fillings are also nice. Try chocolate spread with fresh fruit and cultured whipping cream.

https://www.shipton-mill.com/baking/recipes/sourdough-buckwheat-crepes.htm?print=true

1/2 cup buckwheat flour
2 Tbsp white flour
5 Tbsp sourdough starter
1/4 cup water
1/4 cup milk
1 egg
1/4 tsp salt
butter for cooking

Whisk together all of the ingredients Let the batter rest for at least an hour.
Melt a bit of butter an 8- or 10-inch nonstick skillet and place over medium heat.
Pour a couple of tablespoons of batter into the skillet. Swirl it around so that it forms a thin layer on the bottom of the pan. (If the crêpes doesn’t get thin enough, add a little more milk or water to the batter – I ended up adding about 2 Tbsp water to mine.)
When the top of the crêpes is dry, after about a minute, flip and cook the other side for 15 to 30 seconds. (The crêpes should brown only very slightly and not be at all crisp, or so says Mark Bittman – I actually like my crepes a bit crispy so do as you wish.)
Stack the crêpes on a plate as you make them. You can keep them warm in a low oven while you make the remaining crêpes. Or freeze the leftover crêpes, separating each crêpes with a piece of parchment paper.

https://www.seriouseats.com/2017/05/hot-to-make-french-buckwheat-crepes.html

Annoyingly, there is no itemized recipe, but there is a lot of blah-blah that may contain important info. This site is usually good for that.