Set the wok on a medium heat [large ring] and add the oil and butter
While it’s heating up cut the onion in half, remove the skin and thinly slice with the mandolin
Use the mandolin to thinly slice the garlic too
When the wok is hot, reduce the heat to low and add the onions and garlic
Cook for 8-10 mins until the onions are nice and soft
While the onion is cooking use the mandolin to thinly slice the savoy cabbage, stick it in a colander and give it a good rinse under cold water, leave it to drain while the onion continue to cook, then when the onions are soft add the cabbage, the salt, pepper and sugar to the wok with the onions, give it a good stir around and cook for 5 mins until it softens
Now add the stock and the peas and carry on cooking for 5-10 mins until everything is buttery and delicious
Serve straight away
Great alongside breaded fish or as the green for a roast dinner