01 -
Place the 50 grams of peeled and quartered onion in a blender. Blend for 2 seconds at speed 5, then scrape down the sides with a spatula.
02 -
Add the butter, flour, milk, egg yolk, salt, pepper, and nutmeg. Cook for 8 minutes at 90°C on speed 4.
03 -
Add the 100 grams of grated Emmental cheese to the sauce and cook for another minute at 90°C on speed 4.
04 -
Butter a gratin dish and spread a little Mornay sauce on the bottom. Place a layer of lasagna sheets on top, adjusting the amount as needed.
05 -
Spread 1/4 of the Mornay sauce, then place 2 slices of ham and 1/3 of the raclette cheese. Repeat the assembly with another layer of pasta, 1/3 of the remaining sauce, 2 slices of ham, and raclette cheese. Repeat again with a final layer of pasta, half of the remaining sauce, 2 slices of ham, and the remaining raclette cheese.
06 -
Finish with a final layer of pasta and the remaining Mornay sauce. Sprinkle with 40 grams of Emmental cheese.
07 -
Preheat the oven to 200°C using fan-assisted mode.
08 -
Bake the dish for 20 minutes, until the top is golden brown and bubbly.