In a small bowl mix together the oyster sauce, sugar and water to make the sauce. Set aside.
Heat a large frying pan with oil over high heat. Stir fry the garlic, chilli, spring onions and black bean and garlic sauce until fragrant; 2-3 minutes.
Stir in the onion and salt then cook until soft; 3-4 minutes.
Add the celery, water chestnuts and mushrooms then stir.
Stir in the sauce and yam bundles then cover and simmer for 2-3 minutes.
Add the cornflour slurry and stir until thickened. Serve hot.
Yam bundles are bundles of noodles made from the konjac plant. The noodles are also known as shirataki noodles. They are low in calories and carbohydrates. If you can't find the bundled versions, use shirataki noodles. The noodles can be found in Asian speciality shops or online.
Although some oyster sauces contain oysters many do not choosing to use mushrooms as the prime ingredient thus making them vegetarian and vegan friendly.