Pasta with Butternut Squash, Walnuts, Sage and Grana Padano

Ingredients

• 1 butternut squash, about 1 ½ pounds, peeled and cut into 3/4-inch cubes
• 6 tablespoons extra virgin olive oil
• Kosher salt and freshly ground black pepper
• 3/4 cup toasted walnut halves
• 2 cups vegetable stock
• 4 tablespoons white balsamic vinegar
• 1 clove garlic, minced
• 16 ounces dry farfalle, penne or fusilli pasta
• 12 sage leaves, thinly sliced
• 1/4 cup fresh whole Italian parsley leaves
• ¾ cup finely grated Grana Padano