In a saucepot, over medium heat, add oil and butter. Add onion, carrots and garlic and sweat for 2-3 minutes. Add neck, giblets and livers. Sweat for 2-3 minutes. Add parsley. Season with salt and white pepper. Deglaze with port and add chicken stock.
Bring to a boil and simmer for 20-30 minutes.
Strain and keep warm until ready to use.
Before serving finish sauce with a little unsalted butter.