Heat 2 tablespoons olive oil in a large pot over medium heat and cook the onions and peppers until the onions are translucent and the peppers are soft. Add garlic and heat about two minutes, being careful not to burn it. Deglaze with sherry or wine and cook a few minutes more, adding other optional seasonings as you go.
Add the tomatoes. Having the two different kinds creates a nice variation in texture. Lower heat and let simmer while you cook the meat.
Heat the sausages in boiling water until a white foam forms at the top of the water. Drain, pat dry, and then fry in a skillet with olive oil until cooked through. Cut the sausages into thick slices on a bias and add to the tomato sauce.
Dredge chicken in a mixture of flour seasoned with pinches of salt, pepper, and sage. Heat 2 tablespoons of olive oil in a skillet and fry the chicken on all sides. Deglaze with a bit more wine then scrape the entire contents of the pan into the tomato sauce.
Simmer the cacciatore until delicious, correcting seasonings. Serve with crusty bread.