Marinade the beef steaks with the herbs, chilli, olive oil and fresh seasoning. Grill the steak to the desired temperature before serving. Prepare the couscous according to packet instructions. Remove the mushroom stalks and chop them finely, cook in a knob of butter with the onion and garlic. Add to the prepared couscous, crush in enough brie cheese, parsley and Parmesan. Push this mixture into the mushroom caps, bake in a hot oven for 5 minutes. Trim the beans and blanch in boiling salted water. Cook the onion gently in olive oil until soft, add the bacon and cook until golden. Add the beans, season with salt and pepper; sprinkle with chopped parsley. Peel and chop the potato, cook in salted water until soft. Turn the potatoes in a dry pan and mash with a fork together with the butter, season with salt, pepper and nutmeg, arrange consistency with the cream.