Wash the potatoes and cook covered for about 20 minutes. Drain, quench and peel. Leave to cool.
Clean and wash the spinach. Peel and finely chop the onion. Fry in 1-2 tablespoons of hot oil until translucent. Add the spinach dripping wet and let it collapse. Season with salt, pepper and nutmeg. Drain the spinach.
Mash sheep's cheese with a fork. Stir with crème légère and 1 tablespoon of oil until smooth. Season with pepper. Dice the potatoes. Mix with spinach, spread in a greased casserole dish. Spread sheep's cheese cream on top.
Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for about 25 minutes.
Wash the meat, dab dry and dice. Heat 2 tablespoons of oil in a frying pan. Fry the meat for 6-7 minutes, turning it over. Season with salt and pepper. Spread the meat on the casserole and serve.