Pass the chicken breast in the flour and lightly fry it in a pan with a tbsp of olive oil. Sprinkle it with salt and black pepper. In the meantime, fry the pancetta with a spoon of olive oil in another pan. Add the onion. Transfer the chicken into the pan with the pancetta. Add the wine and let it cook for about 40 minutes, until the chicken is soft. Add the mushrooms and cook for other 10-15 minutes. Take the chicken and cut it into thin slices. If the red wine sauce needs thickening, you can add cream or some besciamelle sauce. Put the chicken back in the sauce, warm up and serve.