Preparing the Marinade:

1. Combine Ingredients: In a mixing bowl, mix 3 tablespoons miso paste, 2 tablespoons soy sauce, 1 tablespoon sugar, 2 tablespoons sake (optional), and 1 tablespoon sesame oil.

2. Add Aromatics: Add 1 teaspoon grated ginger, 1 teaspoon minced garlic, 1 tablespoon mirin (optional), and 1 tablespoon rice vinegar to the mixture. Whisk until smooth.

3. Marinate Salmon: Place the 4 salmon fillets in the bowl, ensuring they are evenly coated with the marinade.

4. Marinating Time: Cover and refrigerate for at least 30 minutes, or up to 2 hours for a deeper flavor. Turn the fillets halfway through for even marination.

Air Frying the Salmon:

5. Preheat Air Fryer: Preheat your air fryer to 400°F (200°C) for about 5 minutes.

6. Prepare Basket: Line the air fryer basket with parchment paper or aluminum foil to prevent sticking and for easy cleanup.

7. Place Salmon: Place the marinated salmon fillets in the basket, skin side down. Ensure they are not touching for even cooking.

8. Cook: Air fry at 400°F (200°C) for 8-10 minutes. Check halfway through to ensure the glaze is not burning. If it is, lower the temperature slightly.

9. Check Doneness: The salmon should be opaque and flake easily with a fork when done.