2 1/2-3-pound skirt steak
2 tablespoons butter
1 large sweet onion, very thinly sliced
1 tablespoon Worcestershire sauce
1 tablespoon tomato paste
2 dried ancho chili peppers, seeded and stemmed
1 1/2 cups chicken stock
Salt and freshly ground black pepper
Extra virgin olive oil (EVOO), for drizzling
Take the steaks out of the refrigerator to take off the chill.
Heat a medium size skillet over medium heat and add the butter. When the butter has melted, add the onion and cook until caramel in color, about 20 minutes. Stir in the Worcestershire sauce and tomato paste. Reduce the heat and simmer for 5 minutes.
Place the anchos in small saucepot with the stock and bring to a boil over medium heat. Turn off the heat and allow the anchos to steep for 5 minutes. Alternatively, put the anchos and stock in a microwave-safe bowl, covered with plastic wrap, and cook in the microwave for 2-3 minutes. Heat a grill pan or grill to high.
Put the anchos and onion in a food processor. Turn the processor on and season with salt and pepper, to taste.
Season the meat with salt and pepper, to taste, and drizzle with EVOO. Grill over high heat for 5-6 minutes total, turning once, for rare. Remove the steak to a cutting board and let rest for 5 minutes. Thinly slice the steak and arrange on a serving platter. Serve with lots of steak sauce poured over top.