Steak Frites Croissant Sandwich by Mamicookss

Ingredients

• 2 ribeye or sirloin steaks (about 200g / 7oz each)
• Salt and black pepper, to season
• 2 tbsp neutral oil
• 2 tbsp unsalted butter (for basting)
• 3 garlic cloves, smashed
• 2 sprigs fresh rosemary
• 1 medium onion, sliced (for peppercorn sauce)
• 120ml (½ cup) beef stock
• 120ml (½ cup) double cream
• 1 tsp Browning sauce
• 1 tbsp whole black peppercorns, lightly crushed
• 1 tbsp fresh parsley, chopped
• 2 medium potatoes, peeled and sliced paper-thin (shoestring fries)
• Oil for deep frying
• 2 medium onions, sliced (for caramelized onions)
• 1 tbsp unsalted butter (for caramelized onions)
• ½ tsp salt
• 1 tsp sugar
• 1 tsp Worcestershire sauce
• 2 large croissants, sliced open

Instructions

1. Season steaks generously on both sides with salt and black pepper.
2. Heat a cast iron or heavy pan over high heat until smoking. Add oil, then sear steaks 2–3 minutes per side. Flip, add butter, smashed garlic, and rosemary, then continuously baste the steak with the foaming butter for 1–2 minutes until your desired doneness. Remove and rest on a board for at least 5 minutes.
3. In the same pan over medium heat, add sliced onion and sauté 3–4 minutes until softened. Pour in beef stock and double cream, stirring to deglaze. Add Browning sauce, crushed peppercorns, and parsley. Simmer 4–5 minutes until the sauce thickens enough to coat a spoon. Set aside.
4. Heat frying oil to 180°C (350°F). Fry paper-thin potato slices in batches for 2–3 minutes until golden and crisp. Drain on paper towels and season immediately with salt.
5. In a separate pan over medium-low heat, sauté the second batch of sliced onions in butter for 5 minutes until translucent. Add salt and sugar, then cook low and slow for 15–20 minutes, stirring occasionally, until deep golden and caramelized. Finish with a dash of Worcestershire sauce.
6. Slice the rested steak as thinly as possible against the grain.
7. Toast the croissants cut-side down in a dry pan for 1 minute until lightly golden. Layer caramelized onions, sliced steak, shoestring fries, and a generous spoon of peppercorn sauce into each croissant. Serve immediately.