Cut the potato into 1cm cubes and soak in water. Drain and microwave for 2–3 minutes at 600W. Cut the onion into 1cm cubes. Break maitake into bite-sized pieces. Slice king oyster mushroom thinly after halving its length.

Cut the bacon into 1cm strips.

Crack eggs into a bowl and mix with mayonnaise, salt, and parsley to create the egg mixture.

Heat 1 tsp vegetable oil in an 18cm frying pan over medium heat. Fry bacon until fragrant, then add onion and cook until translucent. Add maitake, king oyster mushroom, and potato, cooking until mushrooms soften. Season with salt and pepper, then remove and let cool.

Combine the cooled mixture with the egg mixture.