Cook the pasta according to the package instructions. Drain and reserve 1 cup of the cooking water.
While the pasta is cooking, heat the oil in large pan over medium-high heat. Add the onion and cook for about 5 minutes, until it begins to brown.
Add the garlic and cook for a minute or two more.
Add the mushroom and cook for about 5 minutes more minutes, until they have released their liquid and begun to brown.
Add the wine to the pan and deglaze if necessary. Reduce the heat to low and allow it to simmer while you're mixing together the sauce.
In a blender, mix together the cannellini beans, cashews, stock, tomato paste, cornstarch, mustard powder, onion powder, garlic powder, salt, and pepper. Add the mixture to the pan and let simmer for about ten minutes, until it thickens. If it becomes too thick, add a little of the reserved pasta cooking water.
Serve the mushroom mixture over the pasta, topped with parsley.