Found this online for you RE: McDoanlds Sausage
Macdonald’s Pork Sausage Patty
Pork (97%), Salt, Dextrose, Herb and Herb Extract,
Glucose Syrup, Spice, Yeast Extract.
As you will not be able to match this seasoning try the following
55% Salt
20% Dextrose
12% Cornflour
10% Mixed Herbs
2% White Pepper
1% Yeast extract (or pork stock cube)
I see from your earlier comment they seem to have a lot of sage in, in this case change the mixed herbs to half sage & half mixed.
It has a slight bite to it so I'll use this Schilling Pepper seasoning.
Might as well mix by hand as have to shape into patties. Then i can freeze some.
Or I can get some bulk like Bob Evans original and mix it with twice as much as above going easy on everything. Just so it's not a fried ground pork patty.