In a 4 qt saucepan, over medium heat, sauté the onion in a tsp of olive oil until softened. Add the garlic and stir for 1 minute so the garlic does not burn.
Then add the mushrooms. Stir to combine and cook for about 10 minutes, stirring often. When the mushrooms have released their moisture and the pan is almost dry, transfer mushroom mixture to a bowl and set aside.
Into the same pan, add the wild rice and water and a tsp salt. Bring to a boil, then turn heat down to low and simmer, cover pan. Cook for 30 minutes.
While the rice is cooking, in a blender, combine cashews, oats and 2 cups of broth. Blend until smooth and creamy, about a minute.
When the rice is tender, add the remaining 2cups of broth, the mushroom mixture, herbs and the cashew blend to the pot. Bring to a simmer and cook for another ten minutes. The soup is ready when thickened.
Garnish with more fresh herbs and a sprinkling of sliced almonds, if desired.