In a medium bowl, add all of the crepe batter ingredients and whisk together until smooth. Expect the batter to be thinner than normal pancake batter. Refrigerate the batter for at least 30 minutes.
When ready to make the crepes, lightly brush a 6 to 8-inch crepe pan or small nonstick skillet with melted butter and put over medium-high heat.
Ladle a few tablespoons of batter into the center of the hot pan.
Lift the pan, removing it from the heat, and swirl so the batter coats the bottom of the pan in an even layer that's as thin as possible. If you have a few holes in the crepe, you can add a bit more batter to those bald spots to cover them. If there is excess batter in the pan, simply pour it back into the batter bowl.
Return the pan to the heat and cook until the edges crisp and the batter loses its shine, about 45 seconds to 1 minute. Using a nonstick spatula, flip the crepe and continue cooking on the other side, another 30 to 45 seconds.
If making crepes in advance, you can either slide the cooked crepes onto a cookie sheet and keep warm in a 200 degree F oven, or stack on a plate, putting waxed paper between each layer to prevent sticking while you continue with the remaining batter.
When ready to serve, heat 1 crepe in a pan and add some of the filling, warming slightly. (If you imagine your crepe to be divided into quarters, you only want to add filling to the bottom corner in order to fold it properly. The crepe should be folded in half (like you would an omelet) and then again into a neat triangle (like a piece of pie). If you want more filling, crepes can be either rolled or folded in half.)
Combine the sour cream or creme fraiche, lemon zest, lemon juice, dill, chives, and capers, in a small bowl and season with salt and pepper, to taste.
To serve, put a piece of smoked salmon in the bottom corner of a warmed crepe, folding in half (like you would an omelet) and then again into a neat triangle (like a piece of pie). Repeat with remaining crepes and filling. Arrange the crepes on a serving platter. Top each with a dollop of lemon-herb cream and a caper berry before serving.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.