1. Smash ginger rounds to release oils

2. Add smashed ginger rounds, mirin, soy sauce, shallots, and garlic.

3. Set aside 1/4 cup and transfer the rest to a plastic bag.

4. Add fish and marinate for 4 hours to overnight

5. Heat oil over medium-high.

6. Lightly season fish with salt.

7. Sear until golden brown for about 4 minutes.

8. Flip and cook until it has color, about 3 to 4 minutes.

9. Transfer fish to a plate and wipe skillet.

10. Add 1/4 cup of marinade and simmer until it thickens for 1 to 2 minutes.