Place cashews in a bowl and cover with 1 cup of water. Soak for at least 2 hours.Add coconut oil to a large pot and melt over med-high heat.Add onions and sauté for 2-3 minutes or until translucent.Add in mushrooms and continue cooking for another 3 minutes.Lower heat to med-low and cover pot to sweat mushrooms for 5 minutes.Increase heat to high and add in vegetable stock, dried basil, salt and pepper and bring to a boil.Reduce heat and simmer, uncovered for 15 minutes.Remove from heat and let cool for 20 minutes.Add soup and cashews and soaking water to a blender and blend on high until smooth.Serve warm.Will keep for several days in the refrigerator and also freezes well.