Gather the ingredients.
In a blender or food processor, combine 1/2 medium yellow onion, coarsely chopped, 1 canned chipotle in adobo pepper, plus 1 tablespoon of the adobo sauce, 3 large cloves garlic, 1/2 cup chicken broth, 2 1/2 tablespoons freshly squeezed lime juice, 2 tablespoons olive oil, 1 tablespoon chili powder, 2 teaspoons fine salt, 1 teaspoon ground cumin, 1 teaspoon dried oregano, and 1 teaspoon freshly ground black pepper. Process until completely smooth. Adjust the seasoning with salt, if necessary.
Add 6 boneless, skinless chicken thighs, or 4 boneless, skinless chicken breasts to the marinade. Cover and refrigerate for at least 1 hour or for a maximum of 4 hours. If you marinate for too long, the lime juice will actually start to cook the chicken.
When you're ready to cook the chicken, heat your grill pan on high heat.
Sear the chicken on both sides, then turn the heat to medium-low and cook until the juices run clear, or the internal temperature reaches 165 F.
Allow the chicken to rest for at least 5 minutes.
Chop the chicken to your desired size. Divide the 3 cups cooked white or brown rice between 6 bowls. Serve at the table with 2 cups shredded iceberg lettuce, 1 cup cooked black beans, 1 cup shredded Monterey Jack, or cheddar cheese, 1 cup salsa, 1 cup sour cream, and 1 cup guacamole.