Place the dried porcini mushrooms in a bowl and add the room temperature water. Set aside for 30 minutes.

Meanwhile, heat the oil in a large pot over medium heat. Fry the onion until soft and translucent. Add the mushrooms, stir to coat in oil then allow them to brown on the first side before giving them a stir to brown on the other side.

When the mushrooms are soft and browned, add the garlic and fry for another minute to soften.

Remove the rehydrated porcini mushrooms from the water and squeeze them well between your hands to remove as much liquid as possible.

Add the carrots, thyme or sage, bay, rice, vegetable stock, salt and mushroom soaking liquid to the pot. Be careful not to add the dirt and grit from the bottom of the mushroom soaking liquid.

Cover the pot with its lid and bring to a boil. Reduce the heat to a gentle simmer and cook for the length of time indicated on the package of rice (usually about 40 minutes).

Place the cashew butter in a bowl and pour over one or two ladles of the hot soup stock. Stir to dissolve the cashew butter. Chop up the rehydrated porcini mushrooms and add them along with the cashew butter to the pot.

Stir to combine and serve.