Prep the Steak: Pat the hanger steaks dry with paper towels. Season generously on both sides with salt, pepper, and smoked paprika. Let them sit at room temperature for 15 minutes while you prep the couscous.
Toast the Couscous Base: In a medium saucepan over low heat, combine the hot broth (or water) and red pepper flakes. Remove from heat immediately. Stir in the dry couscous, cover tightly with a lid or plastic wrap, and let it steam for exactly 5 minutes. Do not peek.
Fluff and Dress: Remove the lid. Use a fork to fluff the grains gently. Stir in the lemon zest, lemon juice, and butter. The residual heat will melt the butter into the grains. Season with a pinch of salt if needed (broth can be salty). Set aside and keep covered.
Sear the Steak: Heat olive oil in a large skillet over medium-high heat until shimmering. Carefully place steaks in the pan. Cook undisturbed for 3-4 minutes until a deep brown crust forms.
Flip and Finish: Flip the steaks. Cook for another 2-3 minutes for medium-rare, or until an instant-read thermometer registers 130°F (54°C) in the thickest part. Remove from heat.
Rest: Transfer steaks to a cutting board and tent loosely with foil. Let rest for 5 minutes. This allows juices to redistribute.
Serve: Fluff the couscous one last time with parsley. Slice the steak against the grain into thin strips. Serve the meat alongside or on top of the spicy lemon couscous.
