Cook the rice in enough water with a little salt, rinse well under running water and place in a large bowl. Add the sugar, rice vinegar, lemon zest and 1/4 teaspoon salt to the rice that is still warm and stir well. Then let the rice cool down.
In a small pan, carefully roast the sesame seeds without oil over medium heat for about 2 minutes. Slice the cucumber and cut the spring onion into rings. Add to the rice with the sesame seeds. Cut the salmon into small pieces and add.
Mix rapeseed oil, sesame oil, horseradish, lemon juice and dill into a dressing. Season with salt and pepper and mix with the salad.