Greensfor decoration, I have dill and green onions
The first thing to do is to marinate the onion. Red onion cut in half and cut one half lengthwise, long thin "scales". Put in a bowl, pour water with vinegar with added sugar. Let it stand while we prepare the following ingredients. Sour cream is combined with horseradish. I have horseradish with cream, it is not so "evil" and I put 3 tsp to taste. Put horseradish to your taste. Cut the apple into thin slices, removing the middle. I cut half an apple at the rate of 6 sandwiches of 4 thin slices. To prevent the apple slices from darkening, I sprinkled them with a little lemon juice. In a sandwich, they will retain their beautiful and fresh color. It is also good to cut an apple with a ceramic knife, it does not oxidize for a long time. From herring, you need to make a fillet, if it is not ready. The pieces need to be cut into 1 bite.
For sandwiches, I will use buckwheat bread. Suitable for any loaves of this brand: Borodino; rye;... Better those that are not thin. Sour cream will soak them a little, they will be soft and easy to bite off in a sandwich. Spread the first layer of sour cream-horseradish spread. Spread the apple slices. They fit 4 pcs. For apples-herring fillet. They are also 4 pcs. Spread the pickled red onion on top to taste and decorate the sandwiches with dill. Serve immediately.