Season the chicken on both sides with the salt and pepper. Sprinkle the flour on both sides of the chicken, patting it on to make sure it sticks. 

Heat the oil and butter over medium heat in a dutch oven.

Sear the chicken on both sides until lightly golden brown.

Do not crowd the pan, you will need to sear in batches.

Place the chicken on a plate and set aside.

Add the onion, bell pepper, and mushrooms, cook for 5-8 minutes until softened, stirring occasionally.

Add the garlic and cook for an additional 30 seconds until fragrant. 

Deglaze the pan with the wine, scrape the bottom of the pan to release any browned bits.

Add the crushed tomatoes, chicken stock, tomato paste, olives, capers, and Italian seasoning, stir it until combined. 

Add the chicken back into the dutch oven and cover in the sauce.

Cover, reduce the heat to low, and simmer for 30 minutes, until tender and an internal temperature reaches at least 165°F. Stir occasionally to make sure nothing sticks to the bottom of the pan. Serve with a garnish of parsley and parmesan cheese, optional.