Preheat an oven to 180 C.
Mix macadamia nuts, ground waffle seed, bread crumbs, salt and black pepper together in a bowl.
Brush the barramundi fillet with egg white and coat the fish with the nut mix by pressing the nut mix gently a few times until all nuts are firmly covering the fish.
Heat olive oil in a non stick pan on low heat and place the fish with the crusted side first into the pan.
Let the crust brown for 3 minutes, then turn the fish over with a spatula and place the pan in the pre-heated oven for 8-10 minutes.