Preheat the oven to 325°F (160°C). Pat the Veal shank dry and season generously with Salt and freshly ground Black pepper.
Dredge the shanks lightly in All-purpose flour, shaking off excess.
Warm a heavy ovenproof braising pan over medium-high heat and add a splash of Extra-virgin olive oil and a knob of Unsalted butter. Brown the floured shanks on all sides until deeply caramelized, working in batches so the pan isn’t crowded. Remove the shanks and set aside.
Reduce heat to medium and add the finely chopped Onion, Carrot and Celery. Cook, stirring, until softened and beginning to color, then add minced Garlic and cook 30–60 seconds until fragrant.
Pour in the Dry white wine to deglaze the pan, scraping up browned bits; simmer until the wine is reduced by about half.
Return the shanks to the pan, add enough Veal stock to come about two-thirds up the sides of the meat, tuck in a Bay leaf, bring to a simmer, cover, and transfer to the oven. Braise until the meat is very tender and pulls away from the bone, about 1½–2 hours.
While the shanks braise, make the gremolata: finely mince another clove of Garlic (if desired), combine with grated Lemon zest and finely chopped Flat-leaf parsley; set aside.
For the saffron risotto, keep Beef stock hot in a saucepan and crumble a pinch of Saffron threads into a little hot stock to bloom.
In a separate heavy saucepan, melt a tablespoon of Unsalted butter with a splash of Extra-virgin olive oil over medium heat. Add finely chopped Onion and cook until translucent. Add the Carnaroli rice and toast, stirring, for 1–2 minutes until the edges of the grains look translucent.
Deglaze the rice with a splash of Dry white wine and let it absorb. Begin adding the hot stock a ladleful at a time, stirring frequently and allowing each addition to be absorbed before adding the next. After about 12 minutes, stir in the saffron-infused stock and continue cooking until the rice is al dente, about 18–20 minutes total.
When the risotto is creamy and just cooked, remove from heat and stir in a small knob of Beef marrow (if using) and a generous handful of grated Parmigiano Reggiano. Adjust seasoning with Salt and more Black pepper if needed. Let rest for a minute to finish.
To serve, spoon the saffron risotto onto warm plates, top with a Veal shank, ladle over some of the braising juices, and finish with a bright sprinkle of gremolata. Enjoy immediately.
