Preheat oven at 400F with baking tray or cookie sheet
In a zipper bag or on a plate, coat salmon fillet with mixture of cornmeal and cornstarch
Prepare celeriac (and optional sweet potato) for oven fries. Cut off the rough bottom and peel the skin of the main bulb part
Slice celeriac (and sweet potato) into finger-size fries. In a mixing bowl, toss and coat evenly with with 2 tbsp oil
Pour and spread celeriac (and sweet potato) fries over preheated baking tray. Bake for 20 mins, flipping half way if needed
While celeriac fries are baking, heat a cast iron pan over medium heat
Drizzle 2 tbsp oil in heated pan and place coated salmon fillet over oiled pan immediately
Let fillet pan fry on one side for few minutes then flip to other sides. Sprinkle salt and pepper on each side as you go. Attempting to flip too early may cause sticking and break the breading or the fillet
Once all sides are pan fried, check doneness with a pork to see if the fillet is flaky at its thickest part
Remove baked celeriac (and sweet potato) fries from oven. Season with salt and pepper to taste
Plate your fish and chips and enjoy!