Pork Tenderloin with Golden Beets

Name: Pork Tenderloin with Golden Beets
Ingredients: ¼ cup walnuts; 3 tablespoons plus ½ cup olive oil; 1½ pounds pork tenderloin; Kosher salt; 2 medium onions, coarsely chopped; 3 medium golden beets, scrubbed, cut into bite-size pieces; Freshly ground black pepper; 4 garlic cloves, chopped; 2 cups sauerkraut, plus ½ cup brine; 1 cup low-sodium chicken broth; ½ cup dry white wine; 4 tablespoons fresh lemon juice, divided; ½ cup finely chopped mint; ½ cup finely chopped parsley; ¼ cup finely chopped dried tart apricots