Set the oven at 400.
Spray the baking sheet with olive oil.
Spread the potatoes and broccoli out on the baking sheet and drizzle with olive oil. Sprinkle with grated parmesan cheese, garlic powder, salt and pepper.
Put all of the remaining dry ingredients – including the lemon zest – in a bowl and whisk together. Melt the butter in the microwave. In a bowl big enough to handle the filets.
Create your assembly line and one at a time roll the filets in the butter then the dry ingredients. Gently pat them in the dry ingredients to get them evenly coated. Place them in the baking sheet,
Bake for 10 to 15 minutes. Test with a table fork and when the potatoes are easy to poke and the cod wants to flake when you poke it is all done and ready to serve.