Season the yellowtail fillets with a pinch of salt and black pepper.

Heat olive oil in a pan over medium heat.

Add the yellowtail fillets to the pan and cook until golden brown on both sides.

Remove the fish from the pan and set aside.

In the same pan, add minced garlic and king oyster mushrooms. Sauté until mushrooms are tender.

Return the yellowtail to the pan, sprinkle with minced parsley, and adjust seasoning with salt.