In a medium skillet, over a high heat, melt the butter. Saute the mushrooms 3 to 4 minutes. Add the onion, cook until translucent then add the garlic for a minute or so, then the spices. Cook until the mixture is fairly dry. Cool.
In a food processor fitted with a metal blade or blender, chop the cashews finely and slowly; add the oil to make a paste. Add the mushroom mixture and continue mixing until smooth. Taste and add more chile powder or salt, if necessary. Place in a serving bowl and sprinkle with chopped parsley. Serve at room temperature.
Recipe adapted from a recipe courtesy of M.S. Milliken & S. Feniger