Preheat the oven to 220ºC. Rub the cut garlic cloves over the lamb, brush with a little oil, sprinkle with thyme leaves and season with salt and pepper.
Sear in hot pan to brown and finish in the oven for 20 minutes for medium rare.
Remove lamb, cover loosely, rest lamb for 10 minutes before serving. Slice the lamb against the grain and drizzle with the Balsamic syrup.
To make Balsamic syrup: Combine the balsamic vinegar and brown sugar in a small pan, slowly bring to the boil, stirring constantly. Reduce the heat and simmer for 5 minutes until thickened and syrupy.
Served with mashed parsnip and cavolo nero (Tuscan cabbage).
