We took this fish patty from the McDonald’s online recipe sheet, because it turns out that this method actually makes the mock filet-o-fish taste just like the one that you’d get at McDonald’s.
Heat the vegetable oil in a large skillet over medium-high heat an cook the fish until cooked through and golden brown, about 2 minutes a side. Remove the fish from the pan, pat it with a paper towel to remove some of the oil, and season with salt.
Cut the onion in half and soak in cold water for 10 minutes. Remove from the water and mince.
Whisk together miracle whip and the dill relish with a little bit of its juice. Mix thoroughly and then slowly add the sugar, cream of tartar, and the onions. Store in an airtight container and refrigerate until ready to use.
Wrap the bun in a paper towel, and place in the microwave for 10 seconds, this allows the bun to 'sweat' which gives it a buttery taste.
Place the cooked fish filet on top of the bottom bun and add the American cheese, add the tartar sauce and top with the other half of bun.