Heat the vegetable oil in a pan over medium-high heat. Add the garlic and cook until aromatic.
Add the white cabbage and mushrooms. Stir fry for 2–3 minutes.
Add the cauliflower, babycorn and mangetout. Stir fry for a further 2 minutes until the vegetables are just tender but still crisp.
Add the soy sauce and oyster sauce. Toss well to coat the vegetables evenly.
Stir through the beansprouts if using, then remove from the heat and serve immediately.