What's funny is, despite the cookbook calling it Saurbraten style, it technically doesn't fit that definition. You make a sauce out of green apple, onion, apple juice and ginger snaps that it sits in as leftovers, yes, but it's not necessary to full on marinade it.
Anyway, @TC-P I can shoot the recipe to you later. Don't have the book on me right now. It's sweet, sour, and savory with the barest hint of spicy, so it likes to be paired with a somewhat blander potato dish or a more bitter vegetable like broccoli.
When ever you get a chance I would like to try it. Thank you for the offer.