Season the chicken thighs generously with salt and pepper. This layer of seasoning is the foundation of flavor.

In a large skillet or Dutch oven, heat the olive oil over medium-high heat. Sear the chicken thighs, skin-side down first, until the skin is golden and crisp. Turn and brown the other side for a couple of minutes. Remove to a plate and set aside.

In the same pan, add the onion and bell pepper. Sauté until the vegetables soften and the edges start to caramelize, about 5 minutes.

Add the garlic and mushrooms. Cook for 2 minutes until fragrant and the mushrooms begin to brown.

Stir in the tomato paste and cook for 1 minute to deepen its flavor, then pour in the white wine (or chicken broth) to deglaze the pan, scraping up any browned bits from the bottom.

Return the chicken to the pan. Add crushed tomatoes, chicken broth, oregano, thyme, bay leaf, olives, and capers if using. Give everything a gentle stir to combine.

Bring the mixture to a light simmer. Cover and reduce heat to low. Let it braise gently for 25 to 35 minutes, or until the chicken is tender and the flavors meld.

Taste and adjust seasoning with salt and pepper. If you like a thicker sauce, uncover and simmer a few more minutes until it reaches your desired consistency.

Remove the bay leaf. Serve the chicken veiled in sauce over a bed of polenta, pasta, or crusty bread to soak up every bit of deliciousness.