A pestle and mortar is invaluable for jobs like crushing and grinding small amount of spice. You are able to control the grinding very accurately and the weight of the pestle helps with the process. This fine grinding is used in Indian and Southeast Asian cooking where freshly ground spices are preferred.
A pestle and mortar is excellent for lightly crushing soft herb leaves such as mint and basil to release their fragrance for use in dressings. Making garlic mayonnaise is also easier with a pestle and mortar. Soak a slice of white bread in water, squeeze and then crush it in the mortar. Add two peeled cloves of garlic, a pinch of coarse rock salt and pound into a smooth paste. Gradually add a lightly flavored olive oil in drops, mixing vigorously with the pestle. When the mayonnaise has become sufficiently thick. season it with a little lemon juice.
** Asian Recipes