Heat the vegetable oil in a large saucepan over medium heat.

Add the diced onion, minced garlic, diced carrots, and celery sticks.

Sauté everything, stirring occasionally, for about 5 minutes until the vegetables soften.

Add the diced tomato and tomato paste to the pot.

Sauté the mixture for another 2–3 minutes until the tomato softens and the tomato paste caramelizes slightly.

Sprinkle the flour over the vegetables and stir well so that the sauce thickens later.

Add soy sauce, vegan Worcestershire sauce, and the dried herbs.

Mix everything thoroughly so that the flavors can develop.

Gradually pour in the vegetable broth while stirring constantly to avoid lumps.

Reduce the heat to low and let the sauce simmer for about 15–20 minutes until it thickens.

Season the sauce with salt and pepper and add more spices if needed.

If the consistency is too thick, you can add a little more vegetable broth.

Once the sauce has reached the desired consistency and the flavors are well combined, remove it from the heat.

For a smoother consistency, you can optionally puree the sauce in a blender or leave it as is for a more rustic texture.