For the chicken: Pound it down to tenderize. Combine the flour with salt, pepper, paprika, garlic, and onion powder and toss in the chicken to coat.
Add the oil to a skillet and bring to a medium high heat. Remove the chicken from the flour mixture, shaking off any excess and add to the hot oil. Fry until the chicken is golden brown on all sides, about 5 minutes per side. Remove and set aside.
Melt the butter in the same pan and add the onions. Cook until softened and translucent , about 3 minutes. Add in the pancetta. Continue to cook until the pancetta starts to render and crisp. About 10 minutes. Add the garlic and sage and whisk in the stock. Scrap up any bits from the bottom of the pan and simmer until thickened. Mix in the rosemary , mustard and cream continue to simmer until thickened.
Once thickened, add the chicken and green beans. Cover and cook turning the chicken once for 20 minutes.
Serve the chicken and sauce over rice or mashed potatoes. Enjoy!