That's one tasty looking recipe, GG. I saved it, with no promise of ever making it.
PF, beef shank is actually my favorite cut of beef for a veggie soup. Just sayin'...
"Cooking is the art of adjustment." ~~~Jacques Pépin
“A party without cake is just a meeting.” ~Julia Child
"A dream is a festival of lights within your mind." ~~~ Joan Walsh Anglund
I agree with Cooking4to about braising it and then I would leave it in the fridge for a day or two to mellow all the flavors and then freeze it. However, it should confit well but I would remove it from the fat when cooked and set aside for a while until the fat has solidified a bit so that the juice in the bottom can be removed and stored separately for gravy later. This juice could become a bit rancid after a while otherwise I think.( Just my opinion) Warm the now clean fat up enough again for you to return the beef and proceed as usual.
Life is like good wine.......best taken with friends x