Prep the chicken: Pat the chicken dry and season both sides with salt and pepper. For faster cooking, pound thick breasts to even thickness or use cutlets.

Sear the chicken: Heat a large skillet over medium-high heat with a drizzle of olive oil. Sear chicken 4–6 minutes per side until golden and cooked through (165°F internal). Transfer to a plate and tent with foil.

Sauté aromatics: Lower heat to medium. Add a small knob of butter (optional) and minced garlic. Cook 30–60 seconds until fragrant. If using shallot, sauté it first until soft, then add garlic.

Deglaze with broth: Pour in chicken broth and scrape up any browned bits. Let it bubble 2–3 minutes to reduce slightly.

Build the sauce: Whisk in Dijon mustard, thyme, and a pinch of onion powder. Stir in heavy cream. Simmer 3–5 minutes until the sauce thickens enough to coat a spoon.

Adjust the flavor: Add a small squeeze of lemon juice, then taste. Adjust salt, pepper, and Dijon for balance. For more tang, add another teaspoon of Dijon. For extra richness, stir in a pat of butter.

Return the chicken: Nestle the chicken and any juices back into the pan, spoon sauce over the top, and simmer 1–2 minutes to warm through.

Finish and serve: Garnish with chopped parsley or chives. Serve with sautéed green beans, roasted asparagus, cauliflower mash, zucchini noodles, or a simple side salad.