Start the rice: Rinse the brown rice until the water runs mostly clear. In a medium pot, combine rice with broth or water and a pinch of salt.
Bring to a boil, then reduce to a gentle simmer, cover, and cook until tender, about 35–45 minutes. Let it rest 10 minutes off heat, covered, then fluff.
Season the chicken: Pat the chicken dry. Season both sides with salt, pepper, and smoked paprika.
Dry surfaces sear better, so don’t skip patting dry.
Make the sauce base: In a small bowl, whisk together Dijon, whole grain mustard, honey, 1/2 cup broth, and vinegar or lemon juice. Taste and adjust sweetness or tang now.
Sear the chicken: Heat 1 tablespoon olive oil in a large skillet over medium-high. Add chicken in a single layer.
Sear 3–4 minutes per side until golden. Remove to a plate. The chicken will finish cooking in the sauce.
Sauté the garlic: Reduce heat to medium.
Add remaining 1 tablespoon oil if the pan looks dry. Add garlic and cook 30 seconds, stirring, until fragrant. Don’t let it brown.
Build the sauce: Pour in the honey mustard mixture.
Stir, scraping up any browned bits. Bring to a lively simmer.
Finish the chicken: Return the chicken and any juices to the skillet. Spoon sauce over the pieces.
Simmer gently 5–8 minutes, flipping once, until the chicken reaches an internal temperature of 165°F (74°C).
Optional butter swirl: Remove from heat and swirl in the butter for a glossy, restaurant-style finish. Taste and adjust salt, pepper, or acidity.
Serve: Spoon brown rice into bowls or plates. Top with chicken and plenty of sauce.
Sprinkle with chopped parsley or chives. Add a green side if you like.