Using a medium sized pot over medium-high heat, add the oil and bring up to temperature. The oil should be shimmering from the heat, but not smoking.
To the hot oil, add the onion and celery. Cook until very tender.
Add the minced garlic and cubed squash. Stir to combine thorougly. Cook until the squash is tender and soft.
Add the herbs and seasonings to the vegetables (tarragon, thyme, parsley, bay leaves, granulated onion, cayenne, white pepper and salt). Stir to combine and cook together for 5-8 minutes until the mixture has married the seasonings/herbs and vegetables.
Using a high temperature spatula or large kitchen spoon, check to see if most of the juice has cooked down. The vegetables should be cooked soft, but not browned.
Deglaze the pot with ½ cup white wine and reduce until the wine has cooked off, or add the vegetable or chicken stock straight away and stir to incorporate. Allow the soup to heat up the stock.
Make the blonde roux or slurry with corn/potato starch.