Grease 2 small or 1 large gratin dish. Preheat the oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3). Wash the sage, dab dry and remove the leaves. Peel and wash the potatoes and slice or slice them thinly.
Layer with the sage like roof tiles. Season the individual layers with salt and pepper. Pour cream over them. Grate the parmesan and sprinkle half of it on top. Bake in a hot oven for about 45 minutes.
Cut off carrot green to 2-3 cm. Peel, wash and cover the carrots and cook them for 5-6 minutes in little boiling salted water until al dente, drain. Wash the lemon hot, dry it and peel the peel with a pestle ripper or peel it very thin and cut it into fine strips.
Halve the lemon, squeeze one half.
Cut the pancetta into small pieces. Fry in an ovenproof pan or roasting pan without fat until crispy. Drain on kitchen paper. Chop the olives. Knead both with 2 tablespoons butter and the rest of the Parmesan cheese.
Dab fillets dry and tie in shape with kitchen string. Fry them in hot frying fat in a pan or roaster for 2-3 minutes on each side. Season with pepper and a little salt.
As soon as the gratin is ready, switch the oven temperature down (electric oven: 100°C/circulating air and gas not suitable). Leave the gratin in the oven to keep it hot. Cook the steaks in the oven for about 30 minutes.
Then spread the olive mixture on top and gratinate under the hot oven grill for 3-4 minutes.
Meanwhile melt 1 tablespoon of butter. Toss the carrots in it. Sprinkle with 1 tbsp. sugar, caramelise and deglaze with lemon juice. Stir in lemon peel. Serve with steak and gratin.