In a small bowl combine brown sugar, soy sauce, hot water, miso, garlic, ginger and pepper. Whisk to combine.
Place salmon fillets on a plate. Pour half the sauce over the fillets, flip them over, and cover the other side of the salmon with the sauce.
Spray air fryer basket with nonstick vegetable oil spray. Place the sauce-covered salmon into the air fryer basket. Set fryer to 400°F for 12 minutes. Halfway through, brush additional miso sauce on top.
Top fillets with sesame seeds and scallions.
The best way to know if seafood is done enough is to use a meat thermometer. Salmon is done when it reaches an internal temperature of 145F.
You also want silicone-tipped tongs so that you don't inadvertently tear the seafood as you try to turn it.
Don't marinate the fish for too long otherwise, it gets a little bit mealy. I'd say no more than 30 minutes at the outside, but ideally, 5-10 minutes is more than enough.
You can use any leftovers in a salad or over rice if you aren't keto.
You can also use any type of thick fish steaks with the same marinade.
For making in an oven, cook at 400f for 12 minutes and then broil for 1-2 minutes until the top is crispy.