Prepare the dough for the fish profiteroles. Pour milk into a saucepan and add butter. Add salt and place on the fire. Bring to a boil while stirring. Reduce the heat and pour in the flour, stirring quickly. The dough should form a lump. Remove from the heat. When the dough has cooled slightly, add the eggs one by one. After adding each egg, knead the dough until smooth. Eggs should not be added to the hot mixture, otherwise they will curdle. Transfer the dough to a bowl. Add the cottage cheese. Turn on the blender and lightly beat the ingredients. The dough will be thick.
Form the profiteroles. Place the prepared dough in a pastry bag. Press the dough onto a baking sheet at a distance of 2-3 cm from each other. Place in the oven and bake for 20 minutes. Then reduce the temperature to 170℃ and bake for another 10 minutes. Do not open the door during the process. Take the profiteroles out and let them cool.
While the dough is baking, make the red fish mousse. Place the salmon, cream cheese, black pepper and sugar in a blender. Mix for 1-2 minutes until fluffy.
Finish preparing the profiteroles. Cut off the tops of the cooled profiteroles and put the filling inside. Cover with the cut off tops.