Nothing is made fresh in a McDonald's anymore, Everything is prepped outside the store and delivered. I worked there back in the late 80's and early 90's. I used to be a biscuit maker as a crew member, but back then you could go to different stores and get a soft flaky biscuit at one store or a hockey puck at another. To get a more consistent product, McDonald's decided to have them made at an outside place, parbaked and frozen for final cooking in the store. To me the quality went down at the stores who were doing it right, but better at the ones that were like hockey pucks.

Slivered Onions were pre-sliced and brought in bags way back then, so it is nothing new. Lettuce was shredded as well. The restaurants are like assembly plants now. The E.Coli could have come from the onions or the meat, but it should be limited to a certain region as each area usually has its produce grown and cut nearby as well as their meat production.

Just an FYI, When Boston Market first started, only the chicken was cooked in store. All the side dishes were made in central kitchen and delivered multiple times a day until the expansion of stores brought the product to in store production. I was involved in the routing of the trucks back then. Even Dunkin' Donuts uses a central kitchen where the local store finishes them up with the filling and icing.

Hence,

FAST FOOD