For all the trash quality and downhill sliding it is remarkable how much of the flavor profile of a mcdonalds burger is chalked up to just how thin the cooked from frozen patties are and how fast they're cooked, iodized salt, practically only one sad ring of onion reduced into debris, thin and sour pickles and heinz adjacent ketchup and a lacroix flavoring drop of yellow mass market mustard. Like I honestly expected a laundry list of mystery chems to achieve a profile that specific.
If you ever were feeling nostalgic but didn't want to pay 6 dollars for a 60 cent burger that's basically your lot. Just get some el cheapo pure beef frozen patties and a chef press or suitably big ass and heavy food safe weight you can safely handle or even go buck wild and heat up to simulate their weird clamshell griddle thing.
Also I will never forgive them for discontinuing their onion chedder burger.