Prep the chicken. Pat the chicken dry and season both sides with salt, pepper, and Italian seasoning. This helps the sear and builds flavor from the start.

Make a quick balsamic glaze. In a small saucepan, simmer the balsamic vinegar over medium heat until syrupy and reduced by about half (5–7 minutes). Set aside. If using store-bought glaze, you can skip this step.

Sear the chicken. Heat 1 tablespoon olive oil in a large skillet over medium-high. Add chicken in a single layer. Sear 4–5 minutes per side until golden. Remove to a plate. The chicken doesn’t need to be fully cooked yet.

Sauté the aromatics. Lower heat to medium. Add remaining 1 tablespoon olive oil and the garlic. Cook 30 seconds until fragrant. Add the tomatoes, a pinch of salt, and red pepper flakes if using. Cook 3–4 minutes, stirring, until tomatoes start to burst.

Build the pan sauce. Splash in the broth or water (if using) to lift the flavorful bits from the pan. Stir and simmer 1–2 minutes. The tomatoes should be saucy but not soupy.

Finish the chicken. Nestle the chicken back into the skillet. Spoon tomatoes over the top. Cover and cook 3–6 minutes, depending on thickness, until the chicken reaches 165°F in the thickest part.

Add mozzarella. Turn off the heat. Lay mozzarella slices over the chicken. Cover for 1–2 minutes to melt. If you want extra browning, slide the skillet under the broiler for 1 minute (only if your skillet is oven-safe).

Brighten and garnish. Drizzle with the balsamic glaze, squeeze a little lemon over everything, and scatter the torn basil on top. Taste and adjust salt and pepper.

Serve. Spoon the juicy tomatoes over each piece of chicken. Serve with a simple green salad, steamed green beans, zucchini ribbons, or a side of quinoa or whole-grain pasta.