How to make it
In a medium sized pan, heat butter and flour on medium heat. Stir well and cook until golden brown.
Stir garlic, onion, leek, carrots and squash. Cook mixture for 3 minutes.
Add water, thyme, Oyster Sauce and parsley. Cook mixture until vegetables are tender. Cool for 10 minutes.
Transfer mixture into a blender. Process until mixture is smooth.
Return mixture into the sauce pan. Add heavy cream and half and half.
Cook mixture until heated through. Season with salt and pepper.