Julienne slice the onions, braise them in a pan with extra-virgin olive oil, Maldon salt and sherry vinegar.
Do the same with the radicchio.
Let cool and them mix all together in a mixer.
Using plastic wrap, make rolls about 10 cm in length and 2 cm thick. Freeze.
Remove bones from the thighs, beat the meat, salt it and place the stuffing in the centre, roll well and then tie off.
Close everything in a vacuum pack and cook in a Roner at 65°C for 2 hours.
Brown in an oiled pan, then add butter, garlic and thyme.
Let rest for 5 minutes so it cooks through evenly and tenderly.
Place a slice at the centre of the plate, add a slice of braised raddichio and onion and then the lamb juices.