Pat the chicken breasts dry with paper towels. This helps create a better crust when searing.
Season both sides evenly with salt, black pepper, and all purpose seasoning.
Heat oil in a cast iron skillet over medium-high heat.
Add the chicken breasts and cook undisturbed for 4–5 minutes until a deep golden crust forms. Flip and cook for another 3–4 minutes.
Reduce heat to medium and add butter, smashed garlic, and thyme to the skillet.
As the butter melts, tilt the pan and spoon the butter over the chicken continuously for 1–2 minutes. This step adds flavor and keeps the chicken juicy.
Transfer the skillet to a 350°F oven and cook for 8-12 minutes, or until the internal temperature reaches 160–165°F.
Remove the chicken from the skillet and let it rest for 5 minutes before slicing.
Serve whole or sliced, spooning extra butter sauce from the pan over the top.
