In a medium bowl, whisk together balsamic vinegar, Dijon, olive oil, and all seasonings. Add chicken and toss to coat evenly. Let it sit for at least 15 minutes (or up to 12 hours in the fridge).
2 lb chicken breast, 1/2 cup balsamic vinegar, 2 tbsp Dijon mustard, 1 tbsp olive oil, 1 tbsp Italian seasoning, 1 tbsp garlic powder, 1/2 tbsp onion powder, 1 tsp crushed red pepper, 1/2 tsp salt, 1 tsp cracked black pepper