Cut the cauliflower and broccoli florets in ¼ in/6 mm slices. In a wok, heat the peanut oil until very hot, add the ginger and fry for ½-1 minute over high heat. Stir until the ginger browns, then discard it. Add the scallion and carrots and fry, stirring constantly, about 1 minute. Add the cauliflower and continue stirring for 1 minute. Finally add the broccoli, season