If rib eye is a little fancy for your weeknight, try hanger or skirt steaks.

　　

Ingredients

4 servings

　　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

　　

Step 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.

　　

Step 2

Whisk chile, lime juice, 2 Tbsp. olive oil, and remaining 1/2 tsp. demerara sugar in a large bowl; set vinaigrette aside.

　　

Step 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.

　　

Step 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.

　　

Step 5

Slice steak and serve with salad.