1. Combine soy sauce, olive oil, honey, garlic, rosemary, pepper, and salt in a resealable plastic bag. Add the steak, and turn to coat with the marinade; press out excess air, and seal the bag. Marinate in the fridge for 30 minutes, or overnight for better flavor.
2. Preheat an outdoor grill for medium-high heat. Discard marinade.
3. Lightly oil the grill grates. Grill the flank steak for 7 minutes per side, or to desired doneness. An instant-read thermometer inserted into the center should read 140 degrees F (60 degrees C). Let stand for 10 minutes before slicing very thinly against the grain.
4. Drain the chipotle peppers reserving 1 teaspoon of the adobo sauce. Finely chop the chipotle peppers. Stir together the mayonnaise, chipotle peppers, and reserved adobo sauce in a medium bowl. Serve the sauce with the steak.