First we’ll make a roux. Heat the oil in a large pot over medium-low heat. Once warmed, sprinkle over the flour and stir well with a wooden spoon or whisk to remove lumps.

Allow to cook, stirring almost constantly, until a dark chocolate color is reached. This takes about 15 - 20 minutes.

(You can put your spoon down for 20 seconds at a time without ruining it but stir it regularly and keep an eye on it to avoid burning. Also, adjust the heat if you think it’s darkening too fast/slow. Err on the side of slow because it will develop more flavor).

Once you have a dark roux, add the onions and celery and fry, stirring from time to time, until tender - about 5 - 7 minutes.

Add the garlic and fry for 30 seconds.

Add the tomato paste, thyme and bay leaves. Fry for another couple of minutes until darkened.

Add the carrots, potatoes, mushrooms and vegetable stock. Stir well to incorporate the roux. Raise the heat to bring it to a boil then reduce the heat to a simmer.

Simmer until the vegetables are cooked through - about 15 to 20 minutes.

Season with soy sauce. Taste and add salt if you think it’s necessary (I add ½ to 1 teaspoon usually).