Peel and finely dice the onion and garlic. Sort the spinach, wash and drain well. Wash the rosemary, shake dry, put 1 sprig aside for garnishing. Dab meat dry. Place 1 sprig of rosemary around each medallion, wrap 1 slice of bacon around each medallion and pin it with wooden skewers if necessary
Heat the oil in a large frying pan. Fry the meat for about 8 minutes, turning it all round. Remove and season with pepper. Remove wooden skewers if necessary. Sauté onion and garlic in frying fat. Add tomato paste, sweat briefly, add tomatoes and chop with a spatula. Add cream, season with salt, pepper and sugar, simmer for about 10 minutes
Collapse the spinach briefly in a little boiling salted water, drain, rinse with cold water and drain. Stir the spinach into the tomato cream, season to taste. Put about 2/3 of the sauce into an ovenproof casserole dish. Arrange medallions on top. Spread the rest of the tomato cream on top. Bake in a preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: see manufacturer) for approx. 15 minutes. Pluck the rosemary. Remove the casserole dish from the oven and garnish with rosemary. Delicious with baguette bread