Ingredients:

  • 3 Tbsp Unsalted Butter (45g)
  • 3 Tbsp All-Purpose Flour (45g)
  • 1 ½ cups Whole Milk (360ml), warmed
  • ¼ tsp Freshly Grated Nutmeg (1g)
  • Salt & Freshly Ground White Pepper, to taste
  • ¼ cup Grated Gruyère Cheese (30g, or mature Swiss)
  • 8 slices Thick-Cut Bread (e.g., Sourdough or Brioche)
  • 2 Tbsp Dijon Mustard (30ml)
  • 8 oz Cooked Ham (225g, Good Quality, Thinly Sliced)
  • 1 ½ cups Grated Mature Cheddar Cheese (180g, Extra Sharp)
  • Chopped fresh chives or parsley (Optional Garnish)

Instructions:

  1. Melt the butter in a saucepan over medium heat. Whisk in the flour continuously for 1–2 minutes to cook out the raw, pasty taste. This forms the roux.
  2. Gradually whisk in the warm milk, pouring slowly to prevent lumps from forming.
  3. Bring the mixture to a gentle boil, then reduce the heat to low and simmer for 5–7 minutes, stirring occasionally, until the sauce is thick enough to coat the back of a spoon.
  4. Remove the sauce from the heat. Stir in the Gruyère cheese, nutmeg, salt, and white pepper until completely smooth. This is the Mornay sauce. Set aside.
  5. Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper. Lightly toast the 8 slices of bread (optional, but recommended for structure). Lay the slices flat on the prepared baking sheet.
  6. Spread a thin layer of Dijon mustard on the inward-facing side of all 8 slices. On 4 of the slices, layer the sliced ham neatly.
  7. Sprinkle half of the mature Cheddar cheese over the ham layers. Top with the remaining 4 slices of bread, forming the sandwiches.
  8. Ladle a generous amount of the warm Mornay sauce evenly over the top crust of each assembled sandwich, ensuring the entire surface is covered right to the edges. Sprinkle the remaining half of the mature Cheddar over the sauce-covered tops.
  9. Bake for 10–12 minutes until the sauce is bubbling and the edges of the bread are golden brown.
  10. Switch the oven to the broiler (grill) setting. Broil for 1–2 minutes, watching carefully, until the tops are deeply golden and slightly blistered.
  11. Remove from the oven, let rest for 1 minute, slice in half diagonally, and sprinkle with fresh chives or parsley before serving hot.