Lamb fillet & endives' mash

For ➍
5 large potatoes
30 g of butter
600 g lamb fillets (4 pieces)
olive oil
1 leek
2 carrots
½ celeriac

Fry the endives in a casserole with a knob of butter, salt and pepper. Let caramelize.
Peel the potatoes and boil them in salted water. Mash the potatoes in a sieve and mix with the endives. Season with salt and pepper. Also add 2 knobs of butter.
Fry the lamb fillets for 3 m on each side in olive oil. Season with salt and pepper.
Peel the leeks, carrots and celery. Cut into very thin strips and fry it until golden brown at 180°C.
Slice the lamb fillets.

Serve with the endives mash and vegetables.