The secret to the best fried rice is always to use cold cooked rice, not freshly cooked rice. Then the rice will not stick together and the texture will be better.
Pour the egg yolks over the rice and mix well to coat the rice.
Heat the oil in a wok over high heat. Add the rice and stir-fry until the rice is individually separated, loose and does not stick together. Add the onion and carrot and stir-fry for 2 minutes. Add the cucumber and salt and serve.