Ingredients:

  • 4 medium Russet or Maris Piper Potatoes, cut into 1/4-inch batons
  • 4 cups Frying Oil (Peanut, Canola, or Sunflower)
  • 1 teaspoon Fine Sea Salt (for finishing)
  • 2 large Yellow Onions, finely diced
  • 2 tablespoons Unsalted Butter
  • 2 tablespoons Water or Vegetable Stock
  • 1/2 teaspoon Kosher or Sea Salt (for onions)
  • 1/2 cup Mayonnaise (Full-Fat preferred)
  • 1/4 cup Ketchup
  • 2 tablespoons Sweet Pickle Relish
  • 1/2 teaspoon White Wine Vinegar
  • Pinch Granulated Sugar (optional)
  • 4–6 slices American Cheese Slices

Instructions:

  1. Prepare the Potatoes: Cut potatoes into uniform 1/4-inch (6 mm) batons. Place them in a large bowl and cover completely with cold water. Soak for a minimum of 30 minutes (preferably 1 hour) to remove excess starch.
  2. Make the Sauce: In a small bowl, combine mayonnaise, ketchup, pickle relish, vinegar, and sugar (if using). Whisk until completely smooth. Cover and chill in the refrigerator until ready to serve.
  3. Dry the Potatoes: Drain the potatoes completely. Lay them out in a single layer on clean kitchen towels and thoroughly pat them dry. This step is crucial to prevent oil splatter and ensure crispness.
  4. Start the Onions: Melt the butter in a medium frying pan over low heat. Add the diced onions and a generous pinch of salt.
  5. Slow Cook: Cook the onions, stirring frequently, for 25 to 35 minutes until they are deeply dark brown, soft, and jammy—not just translucent.
  6. Deglaze: If the pan bottom starts to stick or brown too quickly, add a tablespoon of water or stock to scrape up the fond (brown bits). Set aside and keep warm.
  7. First Fry (Blanching): Heat the frying oil to 325°F (160°C). Fry the potatoes in small batches for 4–5 minutes until they are soft, pale yellow, and cooked through, but not yet crispy.
  8. Rest: Remove the fries and drain them thoroughly on the wire rack. Allow them to cool completely for at least 10 minutes. This resting period is key for structure.
  9. Second Fry (Crisping): Increase the oil temperature to 375°F (190°C). Return the cooled fries to the hot oil in batches and fry for 2–4 minutes until golden brown and shatteringly crisp.
  10. Drain and Season: Immediately remove the fries from the oil, drain on the rack, and season generously with fine sea salt.
  11. Layer the Components: Transfer the hot, seasoned fries to an oven-safe serving dish or individual portions.
  12. Cheese Melt: Immediately tear the American cheese slices and distribute them evenly over the fries.
  13. Broil/Grill: Place the dish under a hot grill (broiler) for 1–2 minutes, or until the cheese is completely melted and slightly gooey. Watch carefully to avoid burning the fries.
  14. Finish and Serve: Remove the dish. Top the melted cheese and fries liberally with the warm caramelised onions. Drizzle the chilled Secret Spread all over the top. Serve immediately while piping hot.