Prep the chicken: Pat chicken dry and pound to an even 1/2–3/4 inch thickness. Season both sides with salt and pepper.
Heat the pan: Place a large skillet over medium-high heat and add the olive oil.
When the oil shimmers, it’s ready.
Sear the chicken: Add chicken to the pan without crowding. Cook 4–5 minutes on the first side until golden. Flip and cook another 3–4 minutes.
Transfer to a plate; it will finish cooking in the sauce.
Build the glaze: Reduce heat to medium. Add minced garlic and cook 30 seconds until fragrant.
Deglaze: Pour in balsamic vinegar and chicken broth, scraping up any browned bits.
Season and sweeten: Stir in honey, Dijon, red pepper flakes, and thyme or rosemary. Simmer 3–4 minutes until slightly reduced.
Optional thickening: For a stickier glaze, stir in the cornstarch slurry and simmer 1 minute until glossy.
Finish the chicken: Return chicken to the pan.
Spoon sauce over the top and simmer 2–4 minutes, until the chicken reaches 165°F in the thickest part.
Brighten and serve: Taste the sauce and adjust salt, pepper, or honey. Squeeze a little lemon over the chicken if you like. Garnish with parsley and serve with extra glaze from the pan.