Preheat oven to 390 degrees F. Line two baking sheets with parchment paper.
In a pot, add water, butter and salt. Bring to a boil and remove from the heat.
Add flour and mix well, until the dough comes away from the walls and forms into a ball.
Add the eggs one by one. Stir well. The dough should become smooth and shiny.
Place saucepan back on the heat and keep mixing for about 30-50 seconds, to dry out the moisture. Remove from the heat.
Transfer the dough to a piping bag.
Pipe puffs (no bigger than a walnut). Space the puffs on the baking sheet, because the dough will rise.
Lightly brush the top of puffs with egg yolk.
Bake for 20-25 minutes or until the puffs are puffed and golden brown in color. Do not open the oven while baking. Remove from the oven, let them cool down completely and carefully transfer to a flat surface.
Smoked salmon filling
In a food processor, combine the smoked salmon with the onion, garlic, sour cream and olive oil. Process until smooth.
Season with salt, pepper and lemon juice. Mix once more.
Whip heavy cream, until soft peaks form.
Gently fold in salmon mix into the whipped cream. Add the minced fresh dill.
Cut puffs in half. Transfer the filling to a pastry bag and fill the puffs. Replace the top.
Dust puffs with paprika. Serve right away or keep in the refrigerator.