Wash the chicken fillets, dab dry, cut into individual fillets and halve them crosswise. Wrap a slice of bacon around each piece and possibly pin it with a wooden skewer. Peel and halve the onion and cut it into half rings. Wash and drain the cherry tomatoes
Heat 2 tablespoons of oil in a frying pan, fry the chicken medallions vigorously on all sides (4-5 minutes), season with salt and pepper. Remove the medallions from the pan. Add 1 tbsp. oil and onion to the hot frying fat and fry while stirring. Add cherry tomatoes, braise for about 2 minutes and deglaze with chunky tomatoes. Bring to the boil, season with salt, pepper and oregano and simmer for about 3 minutes
Put tomato sauce and chicken-bacon crumbs in a wide casserole dish. Sprinkle with cheese and gratinate in the preheated oven (electric cooker: 250 °C/ circulating air: 225 °C/ gas: see manufacturer) for approx. 10 minutes. Sprinkle with basil leaves. Serve with fresh baguette