Heat the oil in a large skillet over medium heat.
Add the onions and cook until caramel in color, about 20 minutes, stirring occasionally.
As the onions become browner, stir more frequently.
Add the cashew butter, tamari, water and spices and cook until heated through.
Place in a blender or food processor and blend until smooth.
Be careful blending, as hot liquids tend to foam up - fill it only halfway.
*This recipe came from a Penzey's Spices magazine.*