Heat a high-sided skillet over medium heat with the EVOO, about 2 turns of the pan. Add the pancetta and cook for 3-4 minutes, until it starts to get golden.
Add the mushrooms, onion, carrots and bay leaf to the pan. Sauté 4-5 minutes, until the onions start to get tender, then add the garlic and cook another minute or so. Season the veggies with salt and freshly ground black pepper, and add the shredded rotisserie chicken to the pan. Pour in the chicken stock and stewed tomatoes, and bring up to a bubble.