In a small saucepan bring water and achiote seeds to a boil. Cook seeds, covered, at
a bare simmer 30 minutes and remove from heat. (Steep seeds 2 hours, or until softened.)

Heat a dry comal or flat iron griddle over moderately low heat until hot and pan roast garlic and onion, turning them occasionally to ensure even roasting, until browned and soft throughout, 25 to 30 minutes. Discard garlic skins.

In a small heavy skillet dry roast oregano over moderate heat, shaking skillet occasionally, until fragrant and beginning to brown, about 2 minutes and transfer to a small bowl. Cool oregano completely and in an electric coffee/spice grinder grind fine. 

Drain seeds and in a blender or food processor blend with garlic, onion, oregano, and remaining ingredients until smooth. (Recado may be made 5 days ahead and chilled and covered.)
Makes about 2 1/2 cups