Grilled Lamb with Cabbage and Port Wine Sauce

Peel and chop the onions and garlic. Cut the carrot and celery into coarse cubes. Heat a little oil in a large saucepan and roast the vegetables with thyme and bay leaves. Deglaze the pan with balsamic vinegar and cook through. Add port and red wine, and reduce until 1/3 remains. Remove scum at intervals. Add stock and to reduce by half. Sieve the sauce and reduce to an appropriate consistency. Season with salt and pepper. Add cold cubes of butter just before serving if desired. 

Peel the remaining onions and cut into thin rings. Sauté in butter in a small saucepan, without browning the onions. Add vinegar and maybe a little water, put on the lid and steam until tender. Blend with a hand-held blender and season with salt.

Cut or tear the cabbage into suitable pieces and blanch in boiling water for a couple of minutes. 

Season the lamb fillets with salt and pepper and grill until pink inside.  Rest them for 5 minutes and arrange on a plate with pureed onions, cabbage and sauce.