1. Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions. Drain and reserve 1/2 cup of pasta water.
2. Meanwhile, in a large skillet heat butter over medium heat and cook garlic until softened but not brown, about 1 to 2 minutes. Add cream and nutmeg and season with salt and pepper to taste. Cook, stirring occasionally until the sauce is slightly thickened and reduced, about 5 minutes. Add crumbled Gorgonzola and cook, stirring often until the cheese is melted and the sauce has thickened. Stir in the chives.
3. Toss the pasta in the sauce and transfer to serving bowls. Serve with grated Parmigiano-Reggiano if desired.