Preheat the oven at 180 degrees.
Bring water with vinegar to the boil in a large pan; the water must just bubble and not boil.
Cook the eggs one at a time: break them on a plate, let them slip into the water and cook for about 3 minutes. Drain them and let it drip on a clean cloth.
Se the 6 loaves of soft bread or the milk sandwiches cut in half on as many heat-resistant plates, on top of which add a couple of white onion rings and a few basil leaves.
Spread the salmon fillets with a little melted butter and cook them in a hot buttered pan for about 3 minutes on each side, then place them on the donuts.
Place the 6 eggs Benedict on top, seasoned with salt and pepper and bake the 6 dishes for a couple of minutes in the oven. At the same time heat the sour cream in a freshly buttered pan without making it boil, making it more velvety with a couple of tbsp of warm milk.
Take the 6 freshly baked dishes without drying them, cover them with the sour cream sauce, decorate with a little chopped chives and serve.