Cut the spring onion into small rings, cut the mushrooms, habanero and tomato into small slices. Bring a cup of water to a boil in a pan.
As soon as the water boils, add the soba noodles and cook. When the water is almost completely boiled, add the vegetables and beat an egg in the pan. Stir gently and continue cooking on a low temperature until the egg has set. Season with yakisoba sauce.