- In a large pot of salted boiling water, cook the pasta until al dente.
- In the same pot, brown the chicken and onion in the butter and oil. Season with salt and pepper. Add the garlic and cook for 1 minute. Sprinkle with the flour and stir to combine. Add the milk and peas. Bring to boil, stirring with a whisk and simmer gently for 2 to 3 minutes.
- Add the drained pasta, cheese, and nutmeg. Heat until the cheese has melted. Add the chives. Adjust the seasoning.