Start by preparing the sauce. Mix all the sauce ingredients together in a small bowl and set aside.
In a large, high-sided frying pan, add the mushrooms, tofu and kimchi into separate corners of the pan and tip the beans into the centre. Pour the sauce over the beans, followed by the vegetable stock.
Cover the pan and bring to the boil. Reduce the heat and simmer gently for 3–5 minutes, until the mushrooms are just cooked through.
Remove the lid and top with the sliced cheese. Cover again and simmer for a further minute, until the cheese has melted.
Serve immediately, sprinkled with the sliced spring onion.