Pat the flank steak dry with paper towels. Using a sharp knife, lightly score the surface in a diagonal crisscross pattern with shallow cuts about 1 inch apart to help the marinade penetrate.
In a medium bowl or liquid measuring cup, whisk together the soy sauce, canola oil, honey, minced garlic, grated ginger, chili powder, ground cumin, and black pepper until combined.
Place the steak in a gallon zip-top bag. Pour the marinade over the steak, seal the bag removing as much air as possible, and turn the bag to coat the meat evenly. Place the bag in a shallow dish to catch drips.
Refrigerate and marinate the steak for at least 4 hours or up to 24 hours, turning the bag 2 to 3 times during that period.
When ready to cook, remove the steak from the marinade and discard the marinade. Cook the steak to medium-rare (about 130°F). For grilling: cook over high heat about 3 to 4 minutes per side.
For broiling: position the oven rack about 6 inches from the broiler, line a rimmed baking sheet with foil and preheat under the broiler for 5 minutes, then broil the steak without flipping for 6 to 8 minutes until it reaches 130°F.
Transfer the cooked steak to a cutting board and let it rest for 10 minutes. Slice very thinly (about 1/8-inch) against the grain and serve warm.