re: Beef Shank w/ pic

That meat pictured was seared after the sous vide process. Typically I sear on a grill because I like the grill marks and I think it is more appetizing with that method.

I have also seared after in a cast iron skillet and used a chefs torch to sear. I don't like these methods as well.

I think in OP's dish that searing before is the way to go since that cut of beef is typically not suitable for grilling and is generally braised for a long time after the meat is browned. I don't see the appeal for cooking that cut medium rare though and a higher temp might render the fat and connective tissue better yielding a more tender end product.