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.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.