In a large bowl, combine the 4 boneless, skinless chicken breasts, 1/4 cup olive oil, 1/2 cup lemon juice, 1 tablespoon lemon zest minced 1 teaspoon garlic, 1 teaspoon Italian seasoning, 1/3 teaspoon Red pepper chili flakes, 1 teaspoon salt, and 1/2 teaspoon black pepper. Toss to coat the chicken evenly, then cover and refrigerate for at least 30 minutes to let the flavors infuse.