Season the Steak: Coat the thinly sliced beef skirt steak with salt, black pepper, minced garlic, cumin, fresh lime or sour orange juice, and mojo marinade. This mixture tenderizes and flavors the meat deeply. For vegan alternatives, marinate portobello mushrooms or seitan identically.

Marinate: Place the steak in a shallow dish with thinly sliced onions layered on top or mixed in. Marinate for at least 20 minutes; ideally 1 to 3 hours or overnight for optimum flavor absorption and tenderness.

Prepare the Pan or Grill: Heat 2 to 3 tablespoons of neutral oil (vegetable, canola, or avocado) in a large 10-inch nonstick skillet, cast iron pan, or grill over medium-high heat.

Sear the Steak: Remove the steaks from the marinade, shaking off excess. Work in batches to avoid overcrowding, and sear each steak for 1 to 3 minutes per side until a golden-brown crust forms and the desired doneness is reached. Vegetarian substitutes usually require less cooking time avoid overcooking.

Cook the Onions: After cooking the steaks, reduce the heat to medium-low. In the same pan, sauté the thinly sliced onions for 2 to 10 minutes until softened and caramelized, deglazing with a splash of water if necessary to lift flavorful bits from the pan.

Rest and Slice: Let the cooked steak rest for 5 minutes to distribute juices evenly, then slice thinly against the grain for tenderness. Slice plant-based alternatives according to texture.

Serve: Plate the palomilla steak topped with caramelized onions, garnish with fresh parsley or cilantro and lime wedges if desired. Pair with traditional Cuban sides such as white rice, black beans, maduros, or yuca to complete the meal.