Saute onion and garlic in 1 tablespoon oil or water. Add capsicum and cook until soft. Add mushrooms and a minute later, add dill and stir.
In a blender, blend 1/4 cup water with the cashew butter and remaining seasonings. Pour over cooking vegetables. Simmer on low heat and stir for 5 minutes. Serve warm over noodles (see cooking instructions on package of noodles. Use plenty of water).