Asian Steak, Watercress & Spinach Salad with Hoisin Vinaigrette

• 2 bunches watercress (6 to 7 oz. each), thick stems trimmed, tender stems and leaves separated into bite-size sprigs, washed and dried
• 4 oz. baby spinach (about 4 loosely packed cups), washed and dried
• 4 scallions (white and light green parts only), minced
• 1 Tbs. rice vinegar
• 2 tsp. hoisin sauce
• 2 tsp. soy sauce
• 1 tsp. finely grated fresh ginger
• 2 Tbs. toasted sesame oil
• 2 Tbs. vegetable or peanut oil; more for cooking the steak
• Kosher salt and freshly ground black pepper
• 1-1/2 lb. beef strip steaks (about 1 inch thick)
• 1 8-oz. can sliced water chestnuts, drained

Put the watercress and spinach in a large bowl, cover with a damp paper towel, and  refrigerate.

In a small bowl, whisk the minced scallions, vinegar, hoisin sauce, soy sauce, and ginger. Whisk in the sesame oil and vegetable oil. Season to taste with salt and pepper.

Heat a large, heavy pan (preferably cast iron) over medium-high heat for at least 1 min. Use paper towels to pat the steaks dry. Season them generously with salt and pepper. Rub the steaks with oil, put them in the pan and cook them until well browned, about 4 min. Flip the steaks and continue to cook, about another 3 min. for medium rare. Transfer the steaks to a cutting board, let them rest for 5 min., and then slice them thinly.

Add the water chestnuts to the bowl of greens. Whisk the vinaigrette and toss the greens and water chestnuts with just enough of it to coat (there should be a few tablespoons vinaigrette left over). Taste and add salt and pepper as needed. Portion the greens and water chestnuts among four plates. Arrange the beef over the greens, drizzle with any remaining dressing, and serve.