Beef Fillet with Balsamic Vinegar (Filetto all'aceto balsamico)

INGREDIENTS: (4 servings)
4 beef fillet medallions weighing 200g each (800g in total)
80 g butter
1/2 lt meat stock (reduced)
120 g carrots
120 g leeks
120 g young spring onions
1 bouquet garni, (celery, bay leaf, thyme, etc)
20 g fruit chutney
10 g mustard seeds
2 fresh ripe tomatoes
1 sprig of tarragon
Salt
Pepper

Melt 40g butter in a shallow pan and brown the medallions on both sides for a few minutes.
Pour the meat stock into another pan and add the diced vegetables (carrots, leeks and onions), the mustard seeds and the sprig of tarragon.
Gently add the browned medallions, cover and allow to cook for a further eight minutes.
Remove the beef medallions and vegetables from the pan and keep warm.
Dice the tomatoes and place in the pan.
Add the diced fruit chutney and cook for few minutes until the sauce reduces.
Remove the pan from the heat and add the remaining butter to bind the sauce.
Serving suggestion: serve on individual plates: place the vegetables in the middle of the plate, cut the medallions to reveal the pink centre, a sign that they have been cooked to perfection.
Pour two tablespoons of sauce over each, sprinkle with a few drops of traditional balsamic vinegar of Modena, then serve immediately.