Season the chicken. In a bowl, combine salt, pepper, smoked paprika, and Italian seasoning.
Rub this evenly over the chicken on both sides. Let it sit while you prep the vegetables.
Preheat the pan. Heat olive oil in a large skillet over medium-high heat until it shimmers. A hot pan gives you a great sear and keeps the chicken juicy.
Sear the chicken. Add the chicken in a single layer.
Don’t crowd the pan. Cook for 4–5 minutes per side, until golden brown and almost cooked through. Transfer to a plate and tent loosely with foil.
Soften the aromatics. Reduce heat to medium.
Add the onion and a pinch of salt. Cook 2–3 minutes until slightly softened, scraping up any browned bits with a wooden spoon.
Add the vegetables. Stir in the bell pepper and broccoli. Cook 3–4 minutes, stirring occasionally, until they start to soften but still have some bite.
Build the sauce. Add the garlic and cook 30 seconds until fragrant.
Stir in the chicken broth, Dijon mustard, and honey. Bring to a gentle simmer.
Finish the chicken. Nestle the chicken and any juices back into the skillet. Simmer 3–5 minutes, or until the chicken reaches 165°F in the thickest part.
The sauce will slightly reduce.
Enrich and brighten. Turn off the heat. Stir in the butter and lemon juice. Taste and adjust seasoning with more salt, pepper, or lemon if needed.
Serve. Sprinkle with parsley and serve over rice, quinoa, or with crusty bread to soak up the sauce.