Just my 2 cents here but here’s a suggestion MrKing.net
Heres a recipe for the original Big Shef tarter sauce that you can make up in advance
16 oz of salad dressing (I’ve used Miracle Whip but you can also use mayo for a slightly less sweet flavor
3 oz. of rinsed and drained sweet pickle relish (very important to rinse & drain or will be too sweet)
3 oz. reconstituted dried minced onion
dash of hot sauce (optional)
1 tsp dried parsley flakes (optional)
Mix it up and an important step is to let the flavors blend in the fridge for a few days before using.
Head to your local Mc’D’s and order a Big Mac minus their sauce and then add your own. As you so sadly found out at Hardee’s you really need to have that triple decker bun to recreate the tastes and textures properly. The B/K "King Burger" failed against the Mac because there was too much beef and not enough bun I’ve done it and its a pretty good substitute for when I have a Big Shef craving but McD’s burger patties are missing that "Flame Broiled Flavor" that Burger Chef and B/K used to have when your sandwich was assembled with beef that just slid down that greasey chute as it exited the flame broiler.
You can also request a Big Mac sandwich but made with their tarter sauce instead of "special sauce" for a similar effect albeit without the "tanginess" that the original Shef sauce added to the overall taste.