A vegan, plant-based, dairy-free, egg-free, nut-free and gluten-free creamy comforting soup to enjoy on cold winter nights and all year round. Pair with warm crusty bread, whole grain pasta or a gluten-free alternative for a satisfying meal.
In a steamer that is already steaming, cook the chopped cauliflower and a potato for about 10-15 minutes. Test with a fork or knife to see if the potato is cooked through. If so, remove both from the steamer. (Don’t have a steamer? You can roast or microwave cook the cauliflower and potato instead using the methods described in the ‘Notes’ section below. Alternatively, you can improvise to make your own steaming contraption – here’s how.)
Heat half a tablespoon of olive oil in a medium sized soup pot over medium heat. Add the garlic pieces first, sauté for 1-2 minutes, then add the finely diced onions. Cook the garlic and onion pieces for about 5 minutes, until the onion pieces are soft and translucent.
Add in the remaining half tablespoon of oil and then the chopped mushrooms. Stir and sauté the mushrooms for 5 minutes.
Taste and adjust seasonings if needed (e.g., add in more ground black pepper, sherry cooking wine or salt if desired). Let the soup continue to cook on a low medium fire (do not let soup boil), stirring occasionally, for at least 15 -20 minutes (or longer if you desire).
In the last 10 minutes before the soup is served, stir in the cornstarch and water mixture evenly throughout the soup. Stir continuously for at least 2-3 minutes and then let the soup cook on a low heat setting. Once the soup begins to thicken up, turn off the fire. Serve warm.
If the soup appears a little bit on the thin side, don’t worry. As the soup starts to cool down it will thicken up some more on its own. If you have time, you can cook the diced onions down more until caramelized. This will give a richer flavor overall to the mushroom soup.
Choose white button mushrooms rather than the brown Cremini mushrooms for a lighter colored soup. If the final color of the soup doesn’t bother you, then you can just use Cremini mushrooms instead.
You may roast the cauliflower chunks if you prefer (425 F or 218 C) for 25 minutes instead of steam cooking them. Just rub half to one tablespoon of vegetable oil on the cauliflower chunks before placing them on a baking tray and roasting them in the oven. An alternative method is to cook the cauliflower chunks without oil) in a covered dish (sprinkle some water on top of the cauliflower first) and then microwave them for at least 2-3 minutes or until cooked through.
Use any kind of potatoes you like, which can be steamed, boiled or roasted depending on your preference. I have found steaming the potato (along with the cauliflower) to be the easiest and quickest method. However, you could also just microwave the washed potato in a covered dish for 2-3 minutes at a time until cooked through (make sure to poke a few holes with a knife into the potato and sprinkle some water on top first before microwaving).
For an oil-free recipe, use about a ¼ cup of vegetable broth (more if needed) instead of the vegetable oil in the heated pot to sauté the garlic, onion and mushroom pieces.