You can definitely use frozen tuna steaks for this! I usually begin marinating my tuna while it's still frozen. This ensures a perfectly cooked medium-rare tuna steak! If you begin marinating at room temperature, you could easily overcook thee due to the air fryer cooking them so quickly.
If you prefer a more medium doneness or even fully cooked tuna fish steaks, just cook for 2 minutes instead of 1.
Use a meat thermometer! I promise this will not only help you with your fish and seafood recipes but also chicken, pork, and steak recipes! Cooking protein to the correct temperature is always more important than cook time.
Don't use olive oil as a cooking oil for tuna steak. You need something with a high smoke point (avocado oil or coconut oil) so it doesn't burn during the cooking time.
When shopping for tuna at the grocery stores, look for tuna that is cut in uniform thickness, has a deep red coloring, and doesn't have a fishy smell.