Lower oven rack to middle lower position and preheat oven to 450 degrees. Spray heavy duty baking sheet with nonstick cooking spray.
In a large bowl, combine green beans with 1 tablespoon of olive oil, 1/4 teaspoon of kosher salt and 1/4 teaspoon of freshly ground pepper. Arrange green beans in center of baking sheet.
In the same bowl, toss potatoes with 2 tablespoons of olive oil, 1/4 teaspoon of kosher salt and 1/4 teaspoon of freshly ground pepper. Transfer to baking sheet and arrange on either side of green beans, cut side down.
Lay tenderloins, not touching, over green beans and brush with hoisin sauce, sprinkle lightly with salt and pepper. Roast for 20 to 25 minutes, or until thickest part of tenderloins reaches 140 degrees on a meat thermometer.
While tenderloin is roasting, combine butter, chives, garlic, 1/4 teaspoon salt and 1/4 teaspoon pepper. When tenderloin is done cooking, remove sheet pan and top each tenderloin with one tablespoon of garlic herb better and let pork tenderloin rest before slicing.
Top potatoes and green beans with remaining two tablespoons of garlic herb butter and serve.
