Spaghetti with Kale & Walnut Pesto - Once Upon a Chef

Ingredients

• 1 pound spaghetti
• 2 cups packed, torn kale leaves, stems removed
• 1 cup tightly packed fresh basil leaves
• 1 teaspoon salt, plus more for boiling the pasta
• ¼ teaspoon freshly ground black pepper
• ¼ teaspoon sugar
• ½ cup extra virgin olive oil
• ⅓ cup walnuts, toasted if desired (see note)
• 2 medium cloves garlic, roughly chopped
• ½ cup grated pecorino Romano cheese
• ⅓ cup grated pecorino Romano cheese
• ½ cup chopped walnuts, toasted if desired