Author Notes: My new favorite way to grill skirt and flank steak? Marinating them *after*
they’re grilled in a spiky, flavorsome fish sauce vinaigrette. Not only is it a faster path than marinating before grilling, it’s a better path in terms of flavor and texture. By grilling skirt steak naked (with salt, pepper, and a little brown sugar to promote caramelization), it chars beautifully. 

Grilled Steak Salad With Fish Sauce Vinaigrette

Serves: 4 
Prep time: 20 min 
Cook time: 15 min

Ingredients

For the grilled steak and vegetables

• 1pound skirt or flank steak
• 1/2teaspoon kosher salt, plus more to taste
• 1/2teaspoon freshly ground black pepper
• 1teaspoon brown sugar
• 1splash vegetable oil
• 1small bunch of radishes, thinly sliced
• 3/4pound sugar snap peas, trimmed and strings removed
• 1/2cup chopped herbs (I like a mix of cilantro and mint)
• 1handful Sesame seeds, for serving
• 3handfuls watercress or arugula, for serving

For the fish sauce vinaigrette

• 6tablespoons fish sauce (I like Red Boat brand)
• 2tablespoons water, or more as needed
• 3tablespoons lime juice
• 3tablespoons brown sugar
• 1/4teaspoon red pepper flakes, or to taste

Directions

1. To make the vinaigrette: Combine all ingredients in a jar with a tight fitting lid. Shake until the sugar is dissolved. Add another tablespoon of water if it’s too salty/strong. Adjust seasoning and acidity, to taste. Tip: keep the vinaigrette at room temperature so it doesn’t cool down the steaks when used as a post-grill marinade.
2. Pat the steak dry with paper towels, and season both sides evenly with kosher salt, freshly ground black pepper, and brown sugar. Refrigerate while getting the grill ready.
3. Heat the grill to medium-high heat and brush your grates clean.
4. In a bowl, toss the sugar snap peas with 1 tablespoon vegetable oil and season with salt and black pepper to taste. Place a grill tray or mat on the grill grate (to prevent peas from falling through); add peas and arrange in a single layer. Cook 2 to 3 minutes per side, or until tender and charred and still bright green. Transfer to a bowl; set aside.
5. Lightly brush the steak on both sides with vegetable oil. Grill the steak to your desired doneness, 3 to 5 minutes per side (for medium-rare, the internal temperature should reach 130 degrees F). Transfer the steak to a pan or casserole, and pour one-half of the vinaigrette over the steak. Let marinate for about 10 minutes, turning the steak a few times. Transfer to a cutting board, and thinly slice across the grain. Don’t discard the vinaigrette/marinade! Pour it into a small bowl or serving vessel for passing at the table.
6. Meanwhile, toss the grilled sugar snap peas with the sliced radishes. Add vinaigrette to taste, tossing several times to coat. Taste; season with a pinch or two of kosher salt, if needed.
7. On a large serving platter, combine the sugar snap peas, radishes, chopped herbs, watercress, and steak. Sprinkle sesame seeds and drizzle a little more of the vinaigrette over the salad. Serve warm or at room temperature, passing more vinaigrette at the table.

https://food52.com/recipes/76965-grilled-steak-salad-with-fish-sauce-vinaigrette