Beef Tenderloin with Smoky Potatoes and Persillade Relish

Name: Beef Tenderloin with Smoky Potatoes and Persillade Relish
Ingredients: 1 (3-pound) center-cut beef tenderloin roast, trimmed; Salt and pepper; 1 teaspoon baking soda; 3 tablespoons extra-virgin olive oil; 3 pounds extra-small red potatoes , unpeeled; 5 scallions , minced; 4 garlic cloves , minced; 1 tablespoon smoked paprika; 1/2 cup water; 3/4 cup minced fresh parsley; 1/2 cup extra-virgin olive oil; 6 tablespoons minced cornichons plus 1 teaspoon brine; 1/4 cup capers , rinsed and chopped coarse; 1 scallion , minced; 3 garlic cloves , minced; 1 teaspoon sugar; 1/4 teaspoon salt; 1/4 teaspoon pepper