French Onion Sliced Steak Croissant Sandwich

READY IN: 50mins




  • Heat a grill pan or outdoor grill to high; preheat broiler.
  • In a bowl, mix together the garlic, grill seasoning, hot sauce, Worcestershire, and vinegar.
  • Whisk in 3 tablespoons olive oil.
  • Put the flank steak in a shallow dish; pour the marinade over the steak.
  • Toss to coat thoroughly and marinate for 5-10 minutes.
  • While the steak is marinating, heat a large skillet over med-high heat; add in the remaining olive oil.
  • Add in the onions, thyme, salt, and pepper; cook, stirring often, for 7-8 minutes or until the onions are deep golden brown.
  • Add in the chicken stock; continue to cook for 2-3 more minutes or until the chicken stock has almost completely cooked away but the onions are still a little wet with the stock; remove from heat and set aside.
  • Remove the flank steak from the marinade and pat dry.
  • Grill the flank steak for 6-7 minutes on each side; remove steak from the grill to a cutting board; cover loosely with foil and let rest 5 minutes.
  • Thinly slice the steak on an angle, against the grain.
  • Split the croissants in half and place on a cookie sheet, cut sides up.
  • Pile some of the onions on the bottoms of each croissant.
  • Arrange a pile of the sliced steak on top of the onions and then follow that with some more onions.
  • Place slices of cheese on top and transfer both the croissant bottoms and tops to the broiler.
  • Melt the cheese and toast the cut sides of the tops 1-2 minutes.
  • Place the croissant tops on the melted cheese; serve immediately.