Place the chicken breast on a cutting board and cover with plastic wrap. Using a meat mallet or the bottom of skillet, pound until 1/2 inch thick.
In the bottom of a large bowl or casserole dish, add the olive oil, dijon, red wine vinegar, garlic, lemon juice, dried oregano, cumin, kosher salt, and black pepper. Whisk to combine. Place the chicken into the marinade and let marinade for at least 30 minutes, but preferably for 4 to 24 hours.
To grill the chicken, heat grill to medium high heat, about 400°F. Once hot, grill chicken until cooked through, about 4 minutes per side. Serve alongside the Horiatiki Salad.
Greek Style Marinated Chicken · Dinner Match Lab | Dinner Match Lab