Season chicken with salt and pepper and dredge in flour. Heat a few tablespoons EVOO over medium-high heat in a large Dutch oven and brown chicken well, 5 minutes on each side. Remove to plate, add more oil and brown and crumble the sausage. Remove to plate with chicken.
Add fennel, onions, peppers, garlic to the pot and season with salt and pepper. Let soften, 5-7 minutes, then stir in tomato paste. Cook 1 minute, deglaze with wine and add tomatoes and 2 cups stock, breaking up tomatoes. Add reserved sausage and chicken back to the pot, a few leaves of torn basil and simmer 30 minutes, stirring occasionally over low heat.
Bring remaining cup chicken stock and milk to a low boil in a saucepot. Whisk in polenta and thicken 2-3 minutes then stir in butter and cheese.