4 medium boneless, skinless chicken breasts (about 1 1/2 pounds)
1 head broccoli, cut in florets
2 medium garlic cloves, minced
4 tablespoons unsalted butter, divided
4 tablespoons Dijon mustard
1/2 cup low-sodium chicken broth
1/2 cup heavy cream
1 tablespoon fresh thyme leaves, chopped, plus extra for garnish
1/2 teaspoon kosher salt
1/2 teaspoon ground pepper
Preheat oven to 400°F. Grease 2-quart baking dish with cooking spray.
Melt 1 tablespoon butter in large skillet over medium heat. Season chicken breasts with salt and pepper. Cook 3 to 4 minutes per side to brown. Transfer to prepared baking dish.
Add remaining 3 tablespoons butter to skillet. Sauté garlic until fragrant, about 1 minute. Pour in chicken broth and use spoon to loosen any browned bits on bottom of pan. Stir in Dijon mustard, cream, and thyme. Simmer 3 to 5 minutes and stir until thickened.
Pour butter sauce over chicken breasts. Flip chicken to coat both sides. Top with broccoli florets.
Bake in preheated oven 20 to 25 minutes, until broccoli is tender and chicken reaches internal temperature of 165°F. Garnish with fresh thyme leaves is desired.