Panko Crusted Pork Tenderloin with Dijon Cream Sauce

Name: Panko Crusted Pork Tenderloin with Dijon Cream Sauce
Ingredients: 1 (1 1/4 to 1 1/2) pound pork tenderloin; 3/4 cup buttermilk; 1 tablespoon Dijon mustard; 1 tablespoon brown sugar; 1 1/2 teaspoons kosher salt, divided; 1 cup panko breadcrumbs; 1 tablespoon extra virgin olive oil; 1/4 teaspoon freshly ground black pepper; 1 tablespoon butter; 1 small shallot, minced (about 1 to 2 tablespoons); 1 small clove garlic , minced (about 1 teaspoon); 1 cup heavy cream; 1/2 teaspoon Dijon mustard; 1/4 teaspoon kosher salt; 1 pinch black pepper; 2 tablespoons finely chopped fresh parsley