In a small bowl, combine the almonds, breadcrumbs, salt, pepper, herbs, and chile flakes. Mix together to combine. Spread the mixture evenly on a plate.
In another bowl, whisk the egg. Add the honey mustard and whisk again to combine.
Dip the halibut in the egg mixture and coat both sides of the fillet. Then, evenly coat the fillet with the breadcrumb and almond mixture.
Heat the olive oil and butter in a cast-iron pan or other oven-safe frying pan. Brown one side of the fish over medium heat for about 2 minutes. Flip the fillet and place the pan in the oven. Cook for 8-10 minutes, checking at regular intervals after 5 minutes to make sure the fish doesn't dry out.