Step 1: Preheat your oven to 350°F (175°C). Pat the chicken breasts dry thoroughly with paper towels. Season both sides generously with salt and freshly ground black pepper. If breasts are uneven, lightly pound thicker portions to an even thickness of about 1 inch.
Step 2: In a small bowl, whisk together the melted butter, olive oil, garlic powder, onion powder, paprika, dried thyme, and dried oregano until well combined. Brush this mixture evenly over both sides of each chicken breast, ensuring full coverage.
Step 3: Heat a large, oven-safe skillet (preferably cast iron) over medium-high heat until shimmering. Place the seasoned chicken breasts in the hot pan without overcrowding. Sear for about 3 minutes per side, until a beautiful golden-brown crust forms. Avoid moving the chicken during searing to ensure uniform browning.
Step 4: In the same small bowl (or a clean one), whisk together the low-sodium chicken broth, fresh lemon juice, and Dijon mustard. Pour this mixture around the chicken breasts in the skillet, being careful not to pour directly over the seared crust. Transfer the skillet to the preheated oven. Bake for 15-18 minutes, or until an instant-read thermometer inserted into the thickest part of the chicken registers 165°F (74°C).
Step 5: Once cooked, carefully remove the skillet from the oven. Transfer the chicken breasts to a cutting board or serving platter and allow them to rest for 5 minutes. This crucial step allows the juices to redistribute, ensuring tender and succulent results. Spoon any pan juices over the chicken before garnishing with fresh chopped parsley and serving warm.