Prepare dressing by whisking together sour cream, 1/4 cup cilantro, 2 tablespoons lime juice, 2 teaspoons Taco Seasoning, and milk until smooth. Set aside.
Toss together beans, corn, red onion, red bell pepper, remaining 1/4 cup cilantro, and remaining 2 tablespoons lime juice. Season with salt and pepper if desired. Set aside.
Pound chicken breasts to 1/2 -inch thickness. Coat chicken breasts with Roasted Garlic Grapeseed Oil and season with remaining 1 tablespoon Taco Seasoning.
Heat a 10-inch nonstick skillet over medium heat. Add chicken breasts and cook for about 5 minutes on each side or until cooked through: 165°F. Transfer to a cutting board to rest. Slice.
Serve sliced chicken over romaine. Top with bean mixture. Serve with prepared dressing.
Can be served with additional toppings such as diced tomatoes, avocado, shredded cheddar cheese, etc.