Wok-Fried Cucumber with Chillies and Yukari Shiso Salt

Yukari is powdered dried shiso (perilla) leaves mixed with salt, making for a zingy, herbaceous and colourful seasoning. It is deep purple in colour, and normally used over steamed white rice, but also works beautifully in salads and stir-fries. Over a few failed attempts, I discovered that the secret of stir-frying cucumber is adding it only when the wok is seriously hot and smoking, so that it is done fast and before the cucumber releases much of its water. I find the flavour of charred c