Preheat oven to 350 °
Trim chicken pieces of excess fat and skin, then pat dry and season on both sides with salt and pepper.
Heat a large Dutch oven over medium-high heat. When hot add the oil, swirl the pan to coat the bottom, then add chicken, skin-side down, and sear until brown, about 5 minutes.
Turn chicken and brown the other side, about another 3 to 5 minutes.
Remove the chicken to a plate and set aside.
Reduce the heat to medium.
Add the onion and pancetta and sauté until onion is tender, about 8 to 10 minutes.
Add the tomato paste and cook, stirring constantly, for 1 minute.
Deglaze the pan with white wine then add the white beans, chard, and broth.
Season with salt and pepper.
Place the chicken pieces, skin side up, on top of the chard.
Add any accumulated juices from the chicken, top with the rosemary sprigs, and bring to a boil.
Cover and bake about 25 minutes - up to 30 minutes for larger pieces of chicken.
To serve, layer chard and beans in soup plates then top with chicken.
Sprinkle the top with the grated Parmigiano-Reggiano.