Step 1Season the chicken breasts with salt and pepper.
Step 2Combine the mustard and rosemary in a small bowl. Using a pastry brush, coat the chicken breasts evenly with the mustard mixture. Place the bread crumbs in a shallow bowl and, one at a time, roll the chicken breasts in the crumbs, patting them in place.
Step 3Heat the oil in a large skillet over medium-high heat. Cook the chicken until it is browned and cooked through, about 6 minutes a side.