You'll need 3 plates or shallow pans. In the first, place the flour, salt and pepper, mixed thoroughly. In the second, place your egg, lightly beaten; and in the third place your Parmesan cheese, macadamia nuts and 2 tablespoons of your flour mixture, mixed thoroughly.
Rinse the mahi mahi in cool water, and pat dry with paper towels.
Dust lightly in seasoned flour.
Dip in egg wash.
Dip in Parmesan and Mac nuts, push in hard with your hand to coat real thick.
Repeat with each piece of mahi mahi. Let rest for 15 minutes.
Heat canola oil about 1/2" deep in pan, spit in the pan and when it spits back it's ready (drop a drop of water in pan, when it pops, it's hot enough).
Pan fry in canola oil on about medium until flaky (about 3 minutes per side if 1" thick but keep checking it don't overcook).
If making more than one panful, wipe out the pan with paper towel between them and don't crowd.