• Place 16 saffron threads in a small bowl.
• Bring the veal stock to a boil and add a few spoonfuls to the saffron.
• Slice the onion into thin slices.
• Melt the beef marrow and 50g of butter in a large saucepan and gently sauté the onion for 15 minutes until soft.
• Remove the onion from the pan, then add the rice and sauté for 5 minutes, stirring constantly with a wooden spoon.
• Gradually add the veal stock in portions of 1/2 dl at a time, allowing the rice to absorb it while stirring vigorously.
• After 15 minutes, check if the rice is cooked.
• It should be firm to the bite.
• Strain the saffron-infused stock and stir it into the rice for a beautiful yellow color.
• Stir in the remaining saffron threads for extra flavor.
• Remove the risotto from the heat, then stir in the remaining butter and half of the cheese until melted.
• Season with salt, pepper, and a pinch of nutmeg.
• Preheat deep plates and spoon the risotto into them.
• Serve immediately, sprinkling a little cheese on each plate.

For the Gremolata:

• Finely chop the parsley sprigs, mince the garlic cloves, and grate the zest of the thoroughly washed lemon.
• Mix these ingredients together and place it on the table so that each person can add it to their risotto according to their taste.