Step 1

Set the oven to 350° degrees f.

Step 2

Pat the cod: with paper towel to make sure you get all of the excess water out of the fish

Step 3

On a medium-low heat: add your oil to your pan and onions. Fry them for about 5-7 minutes until they soften and golden.

Step 4

Melt butter: in the same pan with the onions and then add your flour. This is how you make the roux.

Step 5

Slowly add the milk: pour the milk into the pan ¼ of a cup at a time and continue to whisk. While the sauce is thickening, you will have a few minutes to grease a baking dish and lay the fish in a single layer on the bottom of it.

Step 6

Once the sauce is thick: add the lemon zest, dijon, and spices. Season the sauce with salt and black pepper to your taste.

Step 7

Pour the sauce: over the fish in the baking dish and then cover with the cheese.

Step 8

Toss the breadcrumbs: with a tablespoon of olive oil and garlic powder and top the baking dish with them. Proceed to bake for 35 minutes. While the cooking time is 35 minutes, you can check it at 30 minutes. If it looks like it is browning too much, you can take it out of the oven.

Step 9

Once it is finished baking: remove from the oven and let sit for 5 minutes. Then serve. You can top with parsley but this is optional.