Peel the carrots and grate in a food processor. Peel the onion and cut in small dices. Peel the ginger and chop finely.
In a hot pan sweat the onion and cook until they turn translucent. Add the carrots and ginger and continue cooking for about two more minutes.
Reduce the heat to a low flame and add the cashew nuts, cumin and coriander powder. Season with salt and pepper.
Cook for about 5 more minutes and add the sour cream. Check the doneness of the carrots, by now they should have cooked well through.
Place the carrots and cashew mixture in a food blender, add the lemon juice and about 100ml water. Blend all together to make a puree but preferably not too fine.
Store in the fridge in an air tight container. In my opinion, the dip tastes better when eaten the next day!