1. Heat some oil in a large skillet over medium heat.

2. Add the diced onion and cook until softened.

3. Add the bacon and cook until crispy.

4. Remove the bacon from the skillet and set aside.

5. In the same skillet, add the boneless chicken and cook until browned on both sides.

6. Add the button mushrooms and cook for a few minutes until they start to soften.

7. Pour in the double cream and stir well to combine.

8. Bring to a simmer and let cook for about 10 minutes, or until the chicken is cooked through and the sauce has thickened.

9. Season with salt and pepper to taste.

10. Serve the creamy mushroom chicken with the crispy bacon on top.

11. Enjoy!