Servings: Serves 8–10
Ingredients 2 Tbsp. plus 1/2 cup extra-virgin olive oil1 large onion , chopped2 large cloves garlic , chopped7 large russet potatoes (4 pounds), peeled and cut into 1-inch cubes10 cups chicken stock1/2 cup chopped toasted walnuts1/2 cup sage leaves1/2 cup parsley leaves1/4 cup grated Pecorino cheese1 tsp. salt plus more salt to tasteFreshly ground pepper
In a large saucepan or stockpot, heat 2 tablespoons olive oil over medium heat. Add onions and cook, stirring occasionally, until caramelized and golden brown, about 12 to 15 minutes. Add garlic and cook, stirring, 30 seconds. Add potatoes and stock, and bring to a boil. Reduce to a simmer; cover and cook 25 to 30 minutes until potatoes are very tender.
Meanwhile, in a food processor combine walnuts, sage, parsley, cheese, and 1 teaspoon salt to make pesto. Pulse until finely ground. With the processor on, slowly add 1/2 cup olive oil. Transfer to a bowl.
Puree soup in batches in a food processor or blender (or with a hand blender). Season to taste with salt and freshly ground pepper. Ladle into bowls and top each with 1 teaspoon of pesto.