Press the garlic cloves into a wide dish, add the milk, bay leaf, fennel seeds and pepper. Turn the meat several times in the mixture.
Cover the meat and marinate in the fridge for approx. 12 hrs.
To brown the meat
Remove the meat from the fridge approx. 1 hr. prior to cooking. Pat the meat dry, season with salt. Heat the clarified butter in a frying pan. Brown the meat on all sides for approx. 8 mins., transfer to the roasting tin.
Slice the onion, fennel and potatoes, remove the sage leaves.
Stir fry all the ingredients in the same pan for approx. 5 mins., season with salt and place around the meat. Wipe the cooking fat from the pan.
Pour the milk into the pan, loosen any bits that have stuck to the bottom, add the crème fraîche, stir and bring to the boil. Mix the cornflour with the reserved milk, add to the pan and simmer for approx. 1 min.
Add the sauce to the meat in the roasting tin.
To roast in the oven
Approx. 40 mins. in the centre of an oven preheated to approx. 180°C. The core temperature should be approx. 60°C. Carve the meat and serve with the vegetables and sauce.