In a large Dutch oven or heavy pot, heat the olive oil over medium-high heat. Season the chicken thighs with salt and pepper, then add them to the pot. Brown the chicken on both sides, about 5 minutes per side. Remove the chicken and set aside.

In the same pot, add the diced onion, carrots, and celery. Sauté for about 5-7 minutes until the vegetables are softened. Add the minced garlic and cook for an additional minute until fragrant.

Pour in the white wine, scraping the bottom of the pot to deglaze. Let it simmer for about 2-3 minutes to reduce slightly.

Stir in the diced tomatoes, chicken broth, thyme, oregano, bay leaf, and return the browned chicken thighs to the pot. Bring to a simmer.

Cover the pot and reduce the heat to low. Let it cook for about 1.5 to 2 hours, or until the chicken is tender and easily pulls apart with a fork.

Once cooked, remove the bay leaf and stir in the lemon zest. Adjust seasoning with salt and pepper if needed.

Serve the chicken osso bucco hot, garnished with fresh parsley.