Preheat oven to 160°C (325°F/Gas 3) or barbecue with a hood to the same temperature. This versatile cooking method allows for either indoor or outdoor preparation.

Season the veal generously with sea salt and freshly ground black pepper. Heat olive oil on a flat plate of a barbecue or in a frying pan over medium heat. Sear the veal on both sides for 2 minutes each, achieving a rich, brown crust.

Transfer the seared veal to a baking dish for oven roasting, or close the barbecue hood to continue cooking outside. Roast for 1 hour and 15 minutes, monitoring until the internal temperature reaches 55-60°C (130-140°F). After roasting, let the veal rest under foil in a warm place for 20-30 minutes, allowing it to continue cooking slightly and ensuring the center remains tender and pink.

For the sauce, blend egg yolks and Dijon mustard in a food processor. Gradually add neutral-tasting oil while the processor runs, forming a smooth mayonnaise base. Enhance this base by incorporating capers, anchovy fillets, tinned tuna (along with its oil), and a splash of lemon juice, blending until smooth.

Mix steamed green beans, sliced tomatoes, slivered red onion, and fresh basil leaves. Dress this vibrant salad with olive oil and a hint of red wine vinegar for a simple, fresh complement to the veal.

Slice the rested veal into 1 cm thick pieces. Arrange the slices on plates, generously topping them with the homemade tuna sauce and a sprinkle of fried capers for an extra burst of flavor. Accompany each serving with a portion of the green bean and tomato salad. This dish is perfectly suited for a warm meal or as a centerpiece for a room-temperature, family-style feast, offering a harmonious blend of flavors and textures that epitomize Italian culinary tradition.