Lard the fillet with cloves of garlic, cut into sticks, as much as you like. Season with salt and freshly ground pepper. Heat sunflower oil in a saucepan and froth a little butter in it. Then brown the whole fillet well on all sides, then put it in the oven preheated to 120 ° C top / bottom heat and let it cook for another 20 minutes, covered. Then wrap the fillet tightly in aluminum foil and put it back in the switched off oven. Deglaze the stock in the casserole on the stove with sweet cream or sour cream - who also likes wine - and season to taste.