Juice 1 orange and add to a food processor or blender.

Add garlic cloves, fresh cilantro, chipotle chiles and their sauce, olive oil, red wine vinegar, ground cumin, ground coriander, and salt to the processor.

Puree the mixture until finely blended.

Place the flank steak in a zip-lock bag.

Pour the cilantro-chipotle marinade over the steak, ensuring it's fully coated.

Seal the bag and chill in the refrigerator for at least 1 hour, or up to 1 day.

Remove the steak from the marinade (discard the used marinade).

Place the steak on a preheated, oiled barbecue grill over medium-high heat.

Cook the steak, turning every 4-5 minutes, until browned and cooked to your desired level of doneness.

Check the internal temperature for medium-rare, approximately 12 minutes total.

Transfer the cooked steak to a cutting board and let it rest for 3-5 minutes.

Thinly slice the steak against the grain.

Slice the remaining orange into segments.

Serve the sliced steak with the fresh orange slices to squeeze over the meat. Add salt to taste.