Put the salmon fillet in a flat saucepan and cover with cold water with wine, lemon juice, broth or fish broth so that the fish is only covered with liquid. Bring to a boil over medium heat, reduce heat and simmer for 5-7 minutes for every 2.5 cm of fish thickness. Cool the fish in the broth.
Rinse all leafy greens, put in a saucepan, adding cold water flush with the leaves. Bring to a boil and simmer over low heat for 30 minutes, pressing the greens from time to time. Throw the boiled greens in a colander, wipe and cool.
Peel cucumbers and finely chop along with onions and dill. Lightly salt and rub with a wooden masher.
Dilute the mashed tops with cold kvass, add crushed cucumbers and greens.
Put ice in the boot. Put thinly sliced fish in each plate, fill with botvinia.