Fill a pot with plenty of waters and bring it to a boil;
If you cover the pot with a lid, water boils faster;
In the meanwhile wash and clean the vegetables;
Cut celery and carrot into coarse pieces;
Half the onion;
Peel the garlic, but don’t crush it;
When the water boils, add wine, vegetables, garlic, aromatic herbs, peppercorns, salt, and oil;
Let the broth boil for about 20 minutes ad then add the meat;
Remove the foam with a skimmer;
If you have a kitchen thermometer, make sure the temperature of the meat doesn’t get over 65°C (149°F);
Simmer for about 1 hour and 30 minutes;
Let the meat cool down completely in its broth;
Remove all the meat net or the string;
Secure the meat with a carving fork, cut it into evenly thin slices with a long sharp straight bladed knife. Use a meat slicer, if you have;
Place the slices onto a serving dish and cover it with the tuna sauce; garnish with desalted capers;
Strain the broth and use it for other recipes (you may also freeze into single servings container, or into an ice mould tray)