- With the rack in the middle position, preheat the oven to 190 °C (375 °F). Line a high-sided baking sheet with parchment paper.
- In a skillet, brown the bacon. Add the mushrooms and sauté until they have rendered their juices. Remove from the heat and add the tomatoes. Season with salt and pepper. Set aside.
- On a cutting board, butterfly the chicken. To do this, place the chicken on its back, stick a knife in the centre and cut through the back bones. You can also ask your butcher to do it.
- Place the chicken (or chickens) flat on the baking sheet. Cover with the butter and mustard. Sprinkle with the breadcrumbs and paprika. Season with salt and pepper.
- Bake for about 50 minutes for small chickens and between 1 hour and 1 hour and 15 minutes for a large chicken. Add the mushroom mixture around the chicken and cook for an additional 15 minutes or until a meat thermometer reads 82 °C (180 °F).
- Cut the chicken into pieces and serve with the mushrooms and rice or mashed potatoes.