Heat the oil in a medium saucepan over medium heat.
Sauté the onion, carrots, celery, and garlic for 5 minutes, or until the onion is soft and translucent.
To make the roux, stir the flour into the vegetable mixture.
Cook for 3 minutes, stirring frequently to toast the flour and prevent it from burning.
Gradually whisk in the vegetable stock until it is fully incorporated into the roux.
Bring the mixture to a boil, then immediately reduce the heat to low.
Stir in the tamari, parsley, rosemary, thyme, sage, and pepper.
Simmer for 10 to 15 minutes, stirring occasionally, allowing the flavors to meld and the gravy to thicken.
Taste and season with salt as needed. For a perfectly smooth consistency, pour the gravy through a fine-mesh strainer before serving hot.
Don't skip the straining step! It's the key to achieving a silky-smooth, professional-quality gravy every time.
