Panko and Mustard Crusted Cod

Modified from The Perfect Pantry.
Ingredients:
2 lb. cod loin (or any mild white fish: cod, halibut, shark, tilapia)
1 c. panko
Zest of two lemons
4 Tbsp. roughly chopped flat-leaf parsley
1 tsp. kosher salt
1/2 tsp. fresh black pepper
2 heaping Tbsp. Dijon mustard
6 Tbsp. olive oil, divided
Lemon wedges, for serving

Preheat the oven to 425°F.
Dry the fish with paper towels, and set in an ovenproof casserole dish. Coat on all sides with 2 Tbsp olive oil.
In a small bowl, mix panko, lemon zest, parsley, salt, pepper, mustard, and 4 Tbsp olive oil, until the panko is moistened. Press the mixture on top of the fish with your hand, to form a thick coating.
Bake for 12-15 minutes, depending on the thickness of your fish; with cod loin, which is at least one inch thick, I baked for 15 minutes. Remove from the oven and let the fish rest for 5 minutes before serving.