Season the chicken generously with salt and pepper. Yes, even that little bit of excess salt will pay off later when the sauce sings.
Heat olive oil in a large skillet over medium-high heat. Sear the chicken until golden on both sides, about 3–4 minutes per side. It won’t be fully cooked through yet—that’s okay; we’ll finish it in the sauce.
Remove chicken and set aside. In the same skillet, add garlic and sauté 30–45 seconds until fragrant. Don’t burn it; burned garlic is the tragedy of the night.
Pour in chicken broth and scrape up all the tasty browned bits from the bottom. Bring to a simmer.
Stir in heavy cream, thyme, and chili flakes. Let it bubble gently for 2–3 minutes, then return chicken to the pan.
Add tomatoes and spinach. Cook until the spinach wilts and the chicken reaches an internal temp of 165°F (74°C). If you don’t have a thermometer, cook until the juices run clear-ish.
Finish with lemon juice, taste, and adjust salt if needed. Spoon sauce over the chicken and plate with a smile.