Stir together all of the ingredients for the marinade in a measuring cup or a mixing bowl until well combined.
Place cod filets in a sealable container or zip lock bag and pour in the marinade. Seal the bag (or container) and move it around until everything is well-coated in marinade. Refrigerate at least 30 minutes, up to 10 hours.
When you’re ready to bake, preheat the oven to 400 degrees F.
Transfer the fish, along with the marinade, to a large casserole dish. Bake on the rack that’s second closest to the top of the oven for 15 minutes, or until fish is completely cooked through.
Serve with choice of side dishes. Go with roasted asparagus and cauliflower rice for a low-carb option, or I suggest my Lemon Garlic Rosemary Rice