Prep the chicken: Pat chicken dry. If using breasts, pound to even thickness (about 1/2 inch) so they cook evenly. Season both sides with salt, pepper, garlic powder, and a pinch of paprika.
Heat the pan: Set a large skillet over medium-high heat.
Add 1 tablespoon olive oil and 1 tablespoon butter. When shimmering, add the chicken in a single layer.
Sear: Cook without moving for 4–5 minutes until golden on the first side. Flip and cook 3–4 minutes more, until the internal temperature hits 165°F (74°C).
Transfer to a plate and tent loosely with foil.
Sauté aromatics: Lower heat to medium. If the pan is dry, add a drizzle of oil. Add chopped onion or shallot and cook 2 minutes.
Stir in minced garlic for 30 seconds, just until fragrant.
Deglaze: Pour in 1/2 cup broth and scrape up the browned bits with a wooden spoon. Let it simmer for 1–2 minutes to reduce slightly. Add a squeeze of lemon or a splash of vinegar for brightness.
Thicken (optional): Stir 1 teaspoon cornstarch into 1 tablespoon water to make a slurry.
Whisk into the pan and simmer 30–60 seconds until lightly thickened. Taste and adjust salt, pepper, and lemon.
Finish: Return chicken and any juices to the pan. Spoon sauce over the top and simmer 1 minute.
Sprinkle with chopped herbs.
Serve: Plate with your chosen starch and veg. Spoon extra sauce over everything for maximum flavor.