Cut the cucumber in half, lengthwise, then slices. Scatter these in a mixing bowl.
Cut the radish into thin wedges, the salad onions into thin slices. Add them to the cucumber.
Add the soy sauce, cider vinegar, toasted sesame oil and half of the sesames seeds. Toss and set aside.
Cut the tofu into 1cm cubes.
Heat the rapeseed oil in a wok and stir fry the tofu cubes for about 5 minutes until light brown. Add the soya sauce and the other half of the sesame seeds. Stir-fry until golden, then transfer to a plate , lined with paper kitchen towel.
When cooled down, add the tofu to salad and toss well.
Serve immediately.