1Heat the oil in a heavy saucepan over medium heat and add the onion. Cook for 5 minutes, stirring frequently, until the onion is soft and translucent. Add the garlic and continue cooking another 2 minutes.
2Add the tomatoes and bring the mixture to a boil. Reduce the heat, and stir in the oregano, coriander, cumin, chipotle seasoning, salt, and sugar. Simmer the mixture for 20 minutes, or until the sauce has thickened slightly. Remove from the heat and cool for 10 minutes.