Cook the rice in 450 ml boiling salted water with 20 g fat for about 20 minutes. In the meantime, peel the cucumber, cut in half lengthwise and remove the core. Cut into pieces of about 2 cm.
Peel and finely chop the onion. Heat the oil in a pot and sauté the onion in it. Add the cucumbers, pour on the stock and stew for about 10 minutes. Season with salt and pepper. Wash the salmon, dab dry and cut into large cubes.
Sprinkle with lemon juice and season with salt and pepper. Heat the remaining fat in a pan and fry the salmon on both sides at medium heat for about 3 minutes. Wash the dill, dab dry and chop finely, except for a little to garnish.
Add the dill to the pan and fry briefly. Stir the sour cream into the cucumbers. Carefully fold salmon with dill and frying fat into the cucumber. Arrange rice with braised cucumbers and salmon on plates. Garnish with dill.