In a bowl mix the eggs, milk and melted butter well with a hand held beater or whisk.
In a seperate bowl, add the all-purpose flour and the buckwheat flour. Whisk it well.
Mix the flour into the wet ingredients. Whisk this well.
Let the batter rest for at least 30 minutes at room temperature.
Whisk the batter each time you are pouring the batter onto the crepe pan.
For a non-stick pan crepe pan, you don't need the fat.
Cook the crepe on one side until well browned. Then flip it over and cook the second side until just browning.
Place the crepes on a plate. If you are going to keep them there for any length of time, place a piece of waxed paper between each crepe. The buckwhest crepes tend to be sticker than the all-purpose flour crepes.