To Prep
To make the cured egg yolks, combine soy sauce and mirin in a bowl. Reserve 3 tbsp of the mixture. Gently add the egg yolks and cover. Place in the fridge for 4 hrs.
Cook rice according to packet directions until tender.
For pickled cabbage, combine rice wine vinegar, sesame oil and sugar in a small bowl. Drizzle over the cabbage and toss until all cabbage is coated. Place in the fridge.
To Cook
Meanwhile, in a medium frying pan, heat a dash of oil over medium to high heat. Cook mushrooms for 2-3 mins. Add carrots and cook, stirring for 2 mins. Add the reserved soy sauce mixture. Simmer for 1-2 mins until vegetables are tender.
Divide the cooked rice between 4 bowls. Add the pickled cabbage, carrots, mushrooms and avocado.
Use a spoon to remove the cured egg yolks from the curing mixture and gently place in the middle of each bowl.
Garnish with spring onion and sprinkle with black sesame seeds. Serve immediately.