Mix 1 cup breadcrumbs, 1 cup yellow cornmeal, 2 tablespoons minced parsley, 2 tablespoons minced thyme, 1 teaspoon salt and 1/2 teaspoon pepper in large bowl.
Whisk 1/2 cup Dijon mustard and 2 eggs in medium bowl to blend.
Using mallet or rolling pin, pound each chicken breast half between sheets of plastic wrap to 1/2- to 1/3-inch thickness. Dip pounded chicken first into mustard mixture and coat well, then into breadcrumb mixture and coat well; shake off excess breadcrumbs.
Melt 2 tablespoons butter with 2 tablespoons oil in heavy large skillet over medium-high heat.
Add half of chicken to skillet; cook until golden, about 2 minutes per side.
Transfer chicken to 13 x 9 x 2-inch glass baking dish. Repeat with remaining butter, oil and chicken.
Bake chicken until cooked through, about 8 minutes.
