For filling
8 oz cream cheese, softened
2 T. fresh lemon juice
1 1/2 teaspoon finely grated fresh lemon zest
Rounded ½ teaspoon coarsely ground black pepper
4 oz thinly sliced smoked salmon
6 medium radishes, cut into 1/8-inch-thick matchsticks (optional)

Make crêpes:
Blend milk, flour, egg, and 2 tablespoons oil in a blender until smooth. Add chives and dill and pulse 1 or 2 times to just combine. Chill batter, covered, 30 minutes.

Stir batter to redistribute herbs. Lightly brush a 10-inch nonstick skillet with oil, then heat over moderately high heat until hot but not smoking. Holding skillet off heat, pour in ¼ cup batter, immediately tilting and rotating skillet to coat bottom. (If batter sets before skillet is coated, reduce heat slightly for next crêpe.) Return skillet to heat and cook until crêpe is just set and pale golden around edges, 10 to 15 seconds. Loosen edge of crêpe with a heatproof plastic spatula, then flip crêpe over carefully. Cook until underside is set, about 20 seconds more. Transfer crêpe to a plate. Make remaining crêpes in same manner, brushing skillet again with oil. You can stack them in layers with wax paper between the layers.

Prepare filling and assemble hors d'oeuvre:
Stir together with a fork: cream cheese, lemon juice, zest, pepper and salmon.

Put 1 crêpe, browned side up, on a work surface, and spread with a couple tablespoons of cheese mixture. Scatter radishes over cheese mixture if using. Beginning at bottom, tightly roll up crêpe, then cut roll crosswise into 4 pieces, trimming ends if desired.

Cooks' Notes:

• Crêpes can be made (but not filled) 1 day ahead and chilled, layered between sheets of wax paper and then wrapped in plastic wrap.
• Cheese mixture can be made 1 day ahead and chilled, covered. Bring to room temperature before using.
• Crêpe can be rolled with filling (but not cut) 1 hour ahead and kept, wrapped in plastic wrap, at room temperature. Cut into pieces just before serving.