Cut the potatoes in half and soak in water for 5 minutes. Drain. Cut the carrot in half lengthwise and then crosswise. Slice the king oyster mushrooms in half lengthwise. Quarter the onion while keeping the core intact.

Cut the pork loin in half and season both sides with salt and pepper.

Heat olive oil in a pot over medium heat and sear the pork until browned on both sides.

Add the soup base ingredients (water, salt, bay leaf, garlic), potatoes, carrots, and onion to the pot. Bring to a boil, cover, and simmer on low heat for 20 minutes.

Add the king oyster mushrooms and simmer for another 5 minutes. Stir in black pepper lightly.