In a large bowl, whisk together vinegar, oil, lemon juice, oregano, garlic, mustard, salt, onion powder, basil, and pepper until well combined. Add chicken, turning to coat. Cover and refrigerate for at least 2 hours or up to overnight.
Let chicken stand at room temperature for 30 minutes. Drain chicken, discarding marinade.
Meanwhile, preheat grill to medium-high heat (350° to 400°). Grill chicken until a meat thermometer inserted in thickest portion registers 165°. Let stand for 5 minutes before serving.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/greek-chicken-pasta-salad-recipe/