Cook penne pasta according to package directions. Reserve ½ cup of pasta water, then drain and set aside.
Heat 2 tablespoons olive oil in a large skillet over medium heat. Add chicken and cook for 5–8 minutes until fully cooked. Season with salt and pepper.
Add chopped peppers and shallots. Cook for 4–7 minutes until slightly browned.
Stir in garlic and cook for 1 minute.
Add balsamic vinegar, lemon juice, remaining olive oil, reserved pasta water, and cooked pasta. Toss everything together and cook for 3–4 minutes. This brings the 30 Minute Chicken Vegetable Skillet Pasta together beautifully.
Transfer to a serving dish and sprinkle with parsley.