01 - 
                Place frozen spinach in the microwave and heat until defrosted. Squeeze out any excess moisture and transfer to a mixing bowl. Add ricotta, harissa paste, black pepper, and salt. Mix thoroughly until evenly combined.
              
              
              
                02 - 
                Arrange salmon fillets flesh side up. Using a sharp knife, carefully make a lengthwise incision down the centre of the thicker portion of each fillet, slicing just to the skin without cutting through.
              
              
              
                03 - 
                Fill each incision with approximately two tablespoons of the ricotta-spinach mixture, gently pressing the filling into the cut.
              
              
              
                04 - 
                Place the stuffed salmon fillets onto a sheet of foil. Drizzle lightly with oil if desired.
              
              
              
                05 - 
                Set the air fryer to 190°C and cook the salmon for 10 minutes. Monitor for doneness, adjusting the time as needed according to your device.
              
              
              
                06 - 
                Remove the salmon from the air fryer and transfer to serving plates. Accompany with pasta, rice, mashed potatoes, or a side of your choice.