Steak With Watercress Salad And Chile-Lime Dressing

• 2 teaspoons Chinese hot mustard powder or English mustard powder (such as Colman's)
• 2 teaspoons fish sauce
• 1 teaspoon demerara or light brown sugar, divided
• Kosher salt, freshly ground pepper
• 1-1 1/2 pounds boneless rib eye
• 1 red Thai chile, very thinly sliced
• 2 tablespoons fresh lime juice
• 2 tablespoons olive oil, plus more for drizzling
• 1 tablespoon vegetable oil
• 2 tablespoons unsalted butter
• 1 bunch watercress, tough stems trimmed (about 6 cups)
• 2 Persian cucumbers, thinly sliced
• 1/4 cup mint leaves
• 1/4 cup salted, dry-roasted peanuts, lightly crushed

1. Whisk mustard powder, fish sauce, 1/2 tsp. demerara sugar, and 1 Tbsp. very hot water in a medium bowl until sugar is dissolved; season with salt and plenty of pepper. Add steak to bowl and turn several times to coat. Let sit while you make the vinaigrette.
2. Whisk chile, lime juice, 2 Tbsp. olive oil, and remaining 1/2 tsp. demerara sugar in a large bowl; set vinaigrette aside.
3. Heat vegetable oil in a medium skillet, preferably cast iron, over medium-high. Add steak and cook, turning every couple of minutes, until nicely browned and medium-rare, 7-10 minutes. Add butter to skillet, then tilt skillet toward you and use a large spoon to baste steak with foaming butter for a minute longer. Transfer steak to a cutting board and let rest 5 minutes.
4. Meanwhile, add watercress, cucumbers, and mint leaves to bowl with reserved vinaigrette and toss to combine; season salad with salt and pepper. Top with peanuts and drizzle with olive oil.
5. Slice steak and serve with salad.

fish sauce, light brown sugar, kosher salt, red thai chile, lime juice, olive oil, vegetable oil, unsalted butter, cucumbers, mint leaves, peanuts

Taken from www.epicurious.com/recipes/food/views/steak-with-watercress-salad-and-chile-lime-dressing (may not work)