Step 1

For Cilantro Dressing, combine lime juice, shallot, cilantro, olive oil, water, honey, garlic, chili powder, salt, and ground cumin in a blender or small food processor. Cover and blend or process until combined. Divide Cilantro Dressing into two portions.

Step 2

For Grilled Flank Steak, trim fat from steak. Score both sides of steak in a diamond pattern by making shallow diagonal cuts at 1-inch intervals. Place steak in a resealable plastic bag. Pour one portion of Cilantro Dressing over steak in bag; set remaining dressing portion aside. Seal bag; turn to coat steak. Marinate in the refrigerator for 30 minutes.

Step 3

Coat sweet pepper, corn, and green onions with cooking spray.

Step 4

For a charcoal grill, grill steak and corn on the rack of an uncovered grill directly over medium coals until steak is desired doneness and corn is tender, turning steak once halfway through grilling and turning corn occasionally. For steak, allow 17 to 21 minutes for medium rare (145 degrees F) to medium (160 degrees F). For corn, allow 15 to 20 minutes. Add sweet pepper halves to the grill for the last 8 minutes of grilling and green onions to the grill for the last 4 minutes grilling, turning frequently. (For a gas grill, preheat grill. Reduce heat to medium. Place meat and, later, vegetables on grill rack over heat. Cover and grill as above.)

Step 5

Thinly slice meat against the grain. Coarsely chop sweet peppers and green onions; cut corn from cob, leaving kernels in "sheets." Serve meat, vegetables, tomatoes, and, if desired, avocado slices over romaine lettuce. Drizzle with the reserved portion of the Cilantro Dressing. Garnish with cilantro sprigs.