To make sure this was tender, I simmered this for 2 hours together with some peppercorns, salt, an onion, garlic and spring onions. Once tender, I lightly fried it in butter. I just wanted to brown it a bit on each side. To make the gravy, I mixed butter and flour in the same pan and added the broth from where the shank was cooked. Carefully add the broth to get the right consistency for the gravy. Season with salt and pepper. Pour the gravy over the shank and top with toasted garlic and chopped spring onions. Enjoy!
That marrow is calling you! :)