Pound and season: If using chicken breasts, pound to even thickness (about 3/4 inch) for quick, even cooking.
Pat dry. Season both sides with salt and pepper.
Mix the sauce: In a bowl, whisk together Dijon mustard, honey, broth, Greek yogurt (or olive oil), lemon juice, apple cider vinegar (if using), garlic, paprika, and red pepper flakes. Taste and adjust honey, lemon, and salt as needed.
You’re aiming for tangy-sweet with a smooth finish.
Sear the chicken: Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add chicken and sear 2–3 minutes per side until golden. Don’t cook through yet; just build color.
Deglaze and simmer: Reduce heat to medium-low.
Pour in the sauce and use a spatula to scrape up the browned bits. Spoon sauce over the chicken and let it simmer gently for 6–10 minutes, flipping once, until the chicken reaches 165°F (74°C).
Rest and thicken: Transfer chicken to a plate to rest 3 minutes. If the sauce is thin, let it bubble for 1–2 minutes to thicken slightly.
If it’s too thick, add a splash of broth.
Finish and serve: Return chicken to the pan and coat with sauce. Garnish with chopped parsley or chives. Serve with steamed broccoli, roasted sweet potatoes, rice, or a crisp salad.