Kroeung is the generic term for a wide array of spice pastes in cambodia. Many cambodian dishes are cooked with kroeung as the base. There are two categories of kroeung: "Royal kroeung" And "Individual kroeung". The terms have nothing to do with social or economic class. Rather, they are descriptive of how the paste is used. "Royal kroeung" Is a standard spice paste that can be used for a number of dishes. "Individual kroeung" Has few or more ingredients added to the paste to suit the specific dish for which it is going to be used. Kroeung is further labeled by color. Red kroeung derives its color from red chilies or their dehydrated pods. Green kroeung has lemongrass as the dominant ingredient. Yellow kroeung gets its color from the amount of turmeric added. This is a recipe for yellow royal kroeung made the traditional way with a pestle and mortar to draw out the natural oils and flavors of each ingredient. If for convenience, you prefer the use of a blender or a food processor, you may need to add a couple of teaspoonfuls of water to help the motor along.