Place the pistachios in the bowl of your food processor and pulse until most of the pistachios are finely chopped, but there are still some bits that are a little more chunky.
Blend chopped pistachios with flax meal and seasoning blend.
Spread this mixture out onto a flat cutting board or plate.
Dip fish filets in the beaten egg and then pat into the pistachio mixtures, coating both sides of the filet. Repeat with however many filets you have.
Heat the cast iron skillet over medium-high heat on the barbecue until it’s sizzling hot. Add the oil and quickly sear the fish on the first side, turning once it looks golden-brown. Repeat on the second side of the filet until the filet. It should cook about 2 minutes per side, depending upon the thickness of the filet.
Remove fish to serving plates and garnish with herbs and a lemon wedge.