Start the cooking process by heating the butter and oil in a large pan that you can put in the oven over medium-high heat. A large Dutch Oven works great for this recipe, but I have also made it in a large fry pan.
While the butter and oil are heating up, dredge the veal shanks in flour, shake off any excess, and then add them to the pan: Brown both sides and the edges.
If your beef shanks are as large as the ones I purchased, you may only be able to cook two at a time. When the browning is done, remove and set aside on a separate plate and continue browning the rest.
When all the shanks are browned and reserved on a plate, lower the heat to medium and add the onion, carrots, and celery. Sauté these ingredients until the onion starts to caramelize. I needed to add a little more olive oil because the pan was too dry.
Add the garlic and anchovy and continue to sauté until you can smell the garlic cooking but be careful not to let it burn.
Add the wine to deglaze the pan and continue cooking it down until there is just a trace of wine left.
Add the stock and tomato to the pan. This is an excellent time to add the Bouquet Garni and the beef shanks.
Bring the stock to a boil, cover and put it into the oven. If you don't have a large Dutch or French Oven and your fry pan is not large enough to hold all the shanks, you will have to transfer them to a large casserole pan with a tight-fitting cover.
I cooked the shanks for 2 hours, turning them shanks over after the first hour. I also basted them every 30 minutes, checking to make sure the stock was not boiling. If it was, I turned down the oven temp a bit.
After two hours with veal shanks, the meat falls off the bone. With the beef shanks, this wasn't the case. The meat was not as tender as I would like it to be. I'm still not sure if it's the meat or if I need to cook them longer. In any case, and my opinion, the veal shanks are generally more tender and have more flavor.
When the shanks are done cooking, remove them and place them on a large serving plate, remove the string and keep warm. Find the bouquet garni, remove it and throw it out. Now it's time to process the wonderful sauce.
I use a hand blender to process the sauce right in the pan, but you can also use a regular blender, a food processor, or a food mill if you have one. Once you process the sauce, taste and adjust the seasoning with salt and pepper.
On a warmed plate, add your mashed potatoes, risotto, pasta, or whatever you decide to serve this with; add one shank and top with a little of the gremolata. I like to have a small bowl of the extra gremolata at the table if anyone wants more.