In a pot of boiling, salted water, cook the pasta according to package directions. Drain and transfer to a large serving bowl.
Meanwhile, in a medium saucepan, heat the EVOO over medium-low heat. Add the garlic and chopped sage and cook, stirring frequently, until the garlic is golden, 1 to 2 minutes.
Whisk in the flour until smooth, about 2 minutes. Gradually whisk in the chicken broth, milk, pepper and nutmeg. Bring to a low boil, stirring constantly. Lower the heat and simmer, stirring gently, until the mixture thickens, about 3 minutes.
Pour the sauce over the pasta and toss. Stir in 3/4 cup parmesan. Top with the sage leaves and more parmesan.