Add all of the ingredients except the chicken to a food processor or blender, and blend for 2-3 minutes, until it is a paste. You can also do this with an immersion blender, but will need to chop the ingredients up a little smaller.
1 tablespoon olive oil, 1/4 cup lime juice, 1/3 cup orange juice, 1/2 can chipotles in adobo, 1/4 cup fresh cilantro, 3 garlic cloves, 1/2 medium onion, 1 teaspoon cumin, 1 teaspoon ground coriander, 3/4 teaspoon smoked paprika, 3/4 tablespoon dried oregano, 1 teaspoon salt, 1/2 teaspoon ground black pepper