Drunken Steak Out

This recipe caught my eye immediately, I can't wait until spring to break out the grill on a nice sunny day! (not that I wouldn't grill when it's 20 below out there)

Ingredients

• For the onions:
• 3 tablespoons butter
• 4 medium onions, sliced
• Salt and pepper
• 2 tablespoons flour
• 1 bottle dark beer, such as Guinness
• 1 tablespoon Worcestershire sauce
• 1 cup beef stock
• For the potatoes:
• 2 pounds potatoes
• Whole milk or half-n-half, for mashing
• 2 tablespoons Dijon mustard
• Salt and pepper
• Grated nutmeg
• 1 small bundle farm spinach, stemmed and chopped
• For the steak:
• 4 flat-iron steaks or 2 pounds flank steaks
• Salt and pepper
• Oil, for drizzling

Preparation
Heat butter over medium heat. Add onions and season with salt and pepper. Cook to very sweet and caramel in color, 25-30 minutes. Add flour and stir 1 minute; add beer, Worcestershire and stock. Reduce heat and gently thicken gravy, 10-15 minutes more.
While onions cook, peel and chop up potatoes. Place them in a large saucepot, cover with water and bring to a boil. Salt water and cook potatoes to tender. Drain and return them to the hot pot. Mash with milk or half-n-half, mustard, salt, pepper and a little nutmeg, to taste. Mash spinach into potatoes to wilt.
While gravy thickens, cook steaks 8-10 minutes on a hot griddle or in a cast-iron skillet over medium-high heat.
Slice steaks and arrange on plates with mashed potatoes and spinach alongside. Top everything with the Drunken Onion Gravy.