Dầu Hạt Điều (Annatto Oil)

Vietnamese cuisine often use annatto oil to enhance a dish with its taste and the vibrant color. Annatto seeds release a beautiful orange color when added to hot oil, but it also adds warm, rich flavor to your dishes. The oil imparts a slightly peppery scent with a nutty hint. 

Annatto shrub with flowers and fruits
http://www.uni-graz.at/~katzer/engl/Bixa_ore.html

Annatto seeds sometimes called roucou or achiote, can be found at spice markets, Asian markets, and in the Mexican foods section of some grocery stores.

If you want to read more about annatto seeds, click on this link: http://en.wikipedia.org/wiki/Annatto

I use a lot of annatto oil in my cooking. I often pre-make a jar of annatto oil and keep it at room temperature for a a few weeks. 

To make annatto oil, add 2 tablespoons of  oil and 2 teaspoons of annato seeds in a saucepan and bring the heat to medium.

As the temperature rises, the red color will leach from the annatto seeds.  The more annatto seeds added to the oil, the deeper of color you will get.

Remove the saucepan from the heat and let stand for a minute. Strain and discard seeds.