Begin by patting the chicken thighs dry with paper towels. Season generously with salt and pepper, then dredge in flour.

In a Dutch oven, heat olive oil and butter over medium-high heat. Sear chicken thighs skin-side down for 4-5 minutes until golden brown. Flip and sear the other side for another 4-5 minutes. Remove chicken and set aside.

In the same pot, add onion, carrots, and celery. Sauté for 6-8 minutes until softened. Stir in garlic and cook for an additional minute.

Pour in white wine to deglaze, scraping up browned bits, and let simmer for 2-3 minutes.

Add crushed tomatoes, chicken broth, thyme, and bay leaf. Mix well to combine.

Return seared chicken to the pot, nestling in the sauce. Bring to a gentle simmer and cover loosely, cooking for 45-60 minutes until tender.

Remove bay leaf and serve hot, garnished with parsley.