Place the shredded coconut in a food processor; pulse very briefly until it is a little more finely shredded.
Add 1/3 cup flour, the cumin, curry powder, salt and pepper; pulse to mix.
Transfer mixture to a shallow plate.
In a small bowl, whisk the egg with 1 tablespoon water.
Place the remaining 1/3 cup flour on a second plate.
Dredge the fillets first in the plain flour (shaking off excess); then in the egg mixture (letting excess drip off); and finally in the coconut mixture; coating both sides completely.
In a skillet, over medium-high heat, heat the olive oil and the butter.
Sauté the fillets until they are browned on both sides and cooked through on the inside; about 2 to 3 minutes per side.
Remove from skillet, spoon a bit of the mango salsa on each fillet and serve.