- 50g soft butter
- 4 thick slices white bread
- 75 grams of grated Gruyere cheese
- 4 slices smoked ham
- 5 tablespoons of cream or milk
- 1 egg yolk
- 1 teaspoon grated Parmesan quality
- A pinch of salt and ground black pepper
- One tablespoon all-purpose flour
Spread the four halves of bread with half the butter and put on a table with greased side down. Melt the remaining butter in a skillet over medium heat and add the flour, salt and pepper. Stir until well blended, then slowly add the milk until the mixture becomes smooth and thick enough to spread.
Remove pan from heat and mix with egg yolk and grated cheese. Then whisk the sauce until all the cheese has melted.
Spread cheese mixture on both sides of the bread is not buttered and sprinkle with half the Parmesan. Fold 2 slices of ham and put in a covered slices of cheese, repeat with remaining slices of ham and slices of bread spread with remaining cheese. Take the remaining slices of bread and put one in each of the slices covered with ham and cheese. Press lightly.
Heat a grill and cook the sandwiches over medium heat for 3 minutes each side until golden and crisp. Sprinkle the rest of the Parmesan on top and leave on grill for another 2 minutes. Remove from grill, cut diagonally (remove the edges if desired) and serve immediately.