Pat dry and season. Blot chicken thighs with paper towels. Season all over with salt and pepper. Dry skin equals better browning.

Sear the chicken. Heat olive oil in a large skillet over medium-high. Place thighs skin-side down and cook until deeply golden and crisp, about 7–9 minutes. Flip and cook another 5–7 minutes. Transfer to a plate. (They’ll finish in the sauce.)

Pour off extra fat. Leave about 1 tablespoon of drippings in the pan. This keeps the sauce rich but not greasy.

Build the base. Lower heat to medium. Add butter. When melted, add garlic and cook 30–60 seconds until fragrant—don’t let it brown.

Deglaze. Add chicken broth and scrape up browned bits. Simmer 2 minutes to reduce slightly.

Cream and season. Stir in heavy cream, Italian seasoning, and red pepper flakes if using. Bring to a gentle simmer.

Add Parmesan. Lower heat and whisk in Parmesan gradually until melted and smooth. If the sauce seems thick, add a splash of broth. If thin, simmer a minute more.

Finish the chicken. Nestle thighs into the sauce, skin-side up. Reduce heat to low, cover loosely, and cook 8–10 minutes, until chicken reaches 175°F internal temperature for tender, pull-apart meat.

Add greens (optional). Stir in spinach and cook 1–2 minutes until wilted.

Brighten and serve. Taste and adjust salt and pepper. Add a squeeze of lemon for balance. Garnish with parsley and extra Parmesan. Serve with pasta, mashed potatoes, rice, or crusty bread.