Place pretzels in a food processor; process until finely crushed. Place pretzels and flour in separate shallow bowls. In another shallow bowl, whisk the eggs, buttermilk, garlic and pepper. Pound chicken with a meat mallet to 1/4-in. thickness. Dip both sides of chicken in flour, egg mixture and then pretzel crumbs.
In a large skillet, heat 3 tablespoons oil over medium heat. Add chicken; cook for 4-6 minutes on each side or until no longer pink.
Meanwhile, in a small bowl, mix mayonnaise and mustard. Remove 2 tablespoons to another bowl for dressing; whisk in remaining oil, vinegar, salt and pepper.
Place salad greens in a large bowl. Drizzle with dressing; toss to coat. Serve with chicken and remaining mayonnaise mixture. Yield: 4 servings (2/3 cup sauce).