Preheat the oven to 392°F.

Wash the spinach thoroughly and cook it in batches in a large pan over medium heat until wilted.

Once the spinach has wilted, use a spoon to press as much moisture as possible out of the spinach in a sieve or colander. Place the drained spinach in a bowl.

Add the ricotta, semi-skimmed milk, a generous pinch of pepper, salt, a splash of lemon juice, and a clove of pressed garlic to the spinach. Mix everything together well.

Grease a baking dish with a little olive oil. Spread about ⅕ of the spinach mixture over the bottom of the baking dish.

Place 3 to 4 lasagne sheets on top of the spinach mixture. Spread another ⅕ of the spinach mixture over this and add the slices of smoked salmon.

Keep repeating this until the spinach mixture, the smoked salmon, and the lasagne sheets are used up. Finish with a layer of the spinach mixture on top.

Sprinkle the top layer with grated Emmentaler cheese. Place the baking dish in the preheated oven for about 45 minutes until the lasagna is cooked through and golden brown.

Remove the lasagna from the oven and let it rest for a few minutes. Enjoy!