Ingredients

• 1/3 cup fresh lime juice (from 3 medium limes)
• 2 Tablespoons minced Jalapeño
• 1-1/2 Tablespoons packed dark brown sugar
• 2 teaspoons fish sauce
• 2 teaspoons  minced garlic
• 2 teaspoons  minced fresh ginger
• 3 Tablespoons canola oil; more for the grill
• 2 Tablespoons Asian sesame oil
• 1/4 teaspoon Xanthium Gum
• 1 lb. flank steak, cut in half lengthwise
• Kosher salt and freshly ground black pepper
• 1 ripe mango, cut into medium dice
• 1/2 small red onion, thinly sliced
• 10 ounces romaine lettuce, sliced crosswise 1 inch thick (about 9 cups)
• 3 Tablespoons chopped fresh cilantro

Preparation

1. Combine the lime juice, jalapeño, brown sugar, fish sauce, garlic, Xanthium gum and ginger in a small bowl.
2. Whisk in both oils in a slow stream; set aside.
3. Prepare a medium-high (400°F to 475°F) gas or charcoal grill fire.
4. Pat the steak dry and season well with salt and pepper.
5. Oil the grill grate and grill the steaks, turning once, until medium rare (135°F), about 6 minutes total.
6. Transfer to a cutting board, let rest for 5 minutes, and then thinly slice across the grain.
7. Meanwhile, in a large bowl, combine the mango, onion, lettuce, and 2 Tableyspoons of the cilantro.
8. Toss with enough dressing to coat, divide the salad among 4 plates, and top with the steak.
9. Drizzle the remaining dressing over the steak, sprinkle with the remaining cilantro, and serve.