Season chicken with salt and pepper on both sides.
Heat EVOO, 2 turns of the pan, in a Dutch oven over medium-high heat. Brown chicken skin-side down first in 2 batches until crispy, remove to plate. Add pancetta, guanciale or bacon and crisp, drain off some fat if there is more than 5-6 tablespoons. Add mushrooms and brown 7-8 minutes. Add fresnos, carrots, garlic, onions, bay, rosemary, thyme, salt and pepper. Partially cover pan and cook 7-8 minutes to soften the vegetables. Stir in tomato paste, cook 1-2 minutes. Add wine and reduce by half. Add tomatoes and basil, break up tomatoes and bring to a simmer. Add chicken back to the pot and simmer 35-40 minutes uncovered to thicken. Stir in parsley near serving time.