Instructions

1. Mix the garlic and the mustard.
2. Thinly slice the leek and mushrooms.
3. Heat a spoonful of oil in a large frying pan. When hot, add the steak and cook for 30 seconds then turn it over and cook for another 30 seconds.
4. Add the sliced vegetables to the pan, next to the steak. Spread half the mustard paste on top of the meat, then turn it over after 30 second and turn down the heat.
5. Spread the remaining paste on top and cook the steak according to your liking, turning it regularly. This should take about 5-5 minutes.
6. Transfer the steak to a plate, cover and rest. Keep cooking the veggies in the pan until tender.
7. Serve the mushroom & leek mixture on the side or on top of the steak.