Pat beef dry with paper towel. 

Stir Dijon mustard into poaching liquid and add haricots verts. 

Cook for 3 minutes or until beans are just tender and transfer to a platter. 

Cover to keep warm. 

Bring liquid to a vigorous simmer to reduce poaching liquid by half, about 5 minutes. 

Meanwhile, transfer beef to a cutting board and slice very thinly, against the grain. 

In a large heavy-bottomed pot or sauté pan, combine cabernet and bouillon and whisk to dissolve. 

Bruise garlic with the side of a knife and add to pan with onion, oregano, thyme, peppercorns and bay leaf. 

Bring the mixture to a gentle simmer, then lower heat until only a few small bubbles are visible on the surface. 

Add beef and cook for 5 minutes on each side for medium rare, 7 minutes a side for medium well. 

Transfer cooked steak to a platter and cover to keep warm while cooking beans.

To serve, divide haricots verts among four plates and top with thinly sliced beef. 

Drizzle with a bit of the reduced poaching liquid, garnish with a few of the poached onions, pepper and salt.