What you do:
1. In a medium mixing bowl, mix together flour and eggs (it’ll be very thick and paste-y; that’s fine).
2. Slowly mix in the milk and water, whisking constantly.
3. Add the salt and butter and beat until smooth.
4. Heat a crepe pan* or frying pan and oil it lightly. Move relatively quickly: you need to start working with the batter right away, or it’ll get lumpy.
5. Scoop about 1/4 cup batter into the center and then tilt the pan in a circular motion until the batter spreads out evenly. These cook fast – just 1-2 minutes total should do it – so monitor closely.
6. Cook until the first side of the crepe is lightly golden, then loosen with a spatula, flip, and cook the other side.
*Crepe pan note: This is a weird and semi-obscure thing to own, but the flat bottom really does help make the crepes spread out evenly, and I use mine all the time for other stuff, as well (it makes great scrambled eggs).
I usually get about 4-5 crepes out of this and fill a couple with Nutella, bananas, and strawberries…