In a large baking dish, whisk cilantro, brown sugar, canola oil, soy sauce, sesame oil, garlic, crushed red pepper, black pepper, and coriander to blend well. Reserve one-fourth cup of the mixture in a small bowl for the slaw. Place steak in the remaining marinade and turn to coat. Marinate for at least 20 minutes at room temperature, or cover and refrigerate for up to one day, turning occasionally. Cover and refrigerate the reserved marinade.

Heat grill pan or outdoor grill over medium heat. Remove steak from the marinade (discard the marinade) and grill, turning halfway through cooking, for a total of about 10 minutes, until the meat reaches an internal temperature of 130 degrees Fahrenheit for medium-rare or 140 degrees Fahrenheit for medium. Transfer the steak to a cutting board and let stand for five to 10 minutes.

In a small bowl, whisk reserved marinade, lime zest, lime juice, and mayonnaise. Stir in slaw and mix.

Heat tortillas on the grill, turning occasionally, for about one minute, or heat on a warming tray or in the oven until hot. Transfer to a serving bowl and cover to keep warm.

Cut steak across the grain into quarter-inch-thick slices. Place a warm tortilla on each individual plate. Put about one-fourth cup slaw in center of each tortilla, followed by two slices of steak. Top with guacamole and cherry tomatoes.