To make annatto oil, combine annatto seeds and your oil of choice (I like olive or peanut oil) in a saucepan and heat over medium high heat. When bubbles start to form around the annatto seeds, turn off the heat and let the seeds soak in the oil for 1 to 2 minutes. Be careful not to burn the seeds because the oil will taste bitter. Transfer the oil to a container using a strainer to filter out the annatto seeds.