Step 1

Preheat an air fryer to 350 degrees F (175 degrees C).

Step 2

Season mahi mahi fillets with salt and pepper and spray with cooking spray on both sides. Place fillets in the air fryer basket, making sure to leave space in between.

Step 3

Cook until fish flakes easily with a fork and has a golden hue, about 12 minutes.

Step 4

While fish is cooking, melt butter in a small saucepan over medium-low heat. Bring butter to a simmer and cook until butter turns frothy and a rich brown color, 3 to 5 minutes. Remove from heat.

Step 5

Transfer fish fillets to a plate and drizzle with brown butter.