If chicken breasts are very thick, carefully slice each horizontally to create two thinner cutlets, or place between two sheets of plastic wrap and pound to about 1/2-inch uniform thickness. This ensures even cooking.

Pat the chicken dry with paper towels. Season both sides of the chicken cutlets evenly with salt, black pepper, garlic powder, and onion powder.

Heat olive oil in a large skillet over medium-high heat until shimmering. Carefully add the seasoned chicken breasts to the hot skillet, ensuring not to overcrowd the pan. Cook in batches if necessary.

Sear for 4-6 minutes per side, or until golden brown and cooked through (internal temperature reaches 165°F / 74°C). Remove the chicken from the skillet and set aside on a plate, tented with foil to keep warm.

Reduce the heat to medium. Add balsamic vinegar, chicken broth, honey (or brown sugar), minced garlic, and Dijon mustard to the same skillet. Whisk well, scraping up any browned bits from the bottom of the pan.

Bring the mixture to a simmer and cook for 3-5 minutes, stirring occasionally, until it has reduced slightly.

In a small bowl, whisk together the cornstarch and cold water until a smooth slurry forms.

Pour the cornstarch slurry into the simmering balsamic mixture in the skillet, whisking continuously. Continue to simmer and whisk for 1-2 minutes, or until the sauce thickens to your desired consistency. It should be thick enough to coat the back of a spoon.

Return the cooked chicken breasts to the skillet, turning them to coat evenly in the warm balsamic glaze.

Spoon additional glaze over the chicken. Garnish with fresh chopped parsley, if desired. Serve immediately with your favorite sides like roasted vegetables, mashed potatoes, or rice.