Pat steak dry with paper towels and sprinkle with 2 teaspoons ras el hanout, ½ teaspoon salt, and ¼ teaspoon pepper. Heat 2 tablespoons vegetable oil in 12-inch nonstick skillet over medium-high heat until just smoking. Add steak and cook until well browned all over and meat registers 120 to 125 degrees (for medium-rare), 7 to 10 minutes, flipping as needed. Transfer to cutting board, tent loosely with aluminum foil, and let rest while cooking couscous.

Add 1¼ cups water, couscous, ½ teaspoon salt, and remaining ½ teaspoon ras el hanout to now-empty skillet and bring to boil over medium-high heat. Remove from heat, cover, and let sit until couscous is tender, about 5 minutes.

Fluff couscous with fork, stir in spinach and pomegranate seeds, and season with salt and pepper to taste. Slice steak thin and serve with couscous.