Gently fry the diced onion in oil. After 5 min add the finely chopped garlic.

NextAdd the sliced mushrooms and let them release their water.

Add the sliced mushrooms and let them release their water.

NextAdd the bacon in thin strips, let it cook a little and add the chopped ham.

Add the bacon in thin strips, let it cook a little and add the chopped ham.

NextAfter a couple of minutes, add the tomato (except a couple of tablespoons), stir well and add the spinach and salt.

After a couple of minutes, add the tomato (except a couple of tablespoons), stir well and add the spinach and salt.

NextLet it cook over a low heat until the tomato has reduced.

Let it cook over a low heat until the tomato has reduced.

NextAdd 2 or 3 tablespoons of the béchamel to the filling.

Add 2 or 3 tablespoons of the béchamel to the filling.

NextPrepare the lasagne sheets according to the packet instructions.

Prepare the lasagne sheets according to the packet instructions.

NextMelt the butter in the pan and add the flour. Stir well until it forms a paste.

Melt the butter in the pan and add the flour. Stir well until it forms a paste.

NextAdd the hot milk little by little until it has a béchamel texture. For a thinner sauce, add more hot milk.

Add the hot milk little by little until it has a béchamel texture. For a thinner sauce, add more hot milk.

NextLay two sheets side by side in the baking dish, cover with 2 tablespoons of béchamel, add the filling and a little Emmental.

Lay two sheets side by side in the baking dish, cover with 2 tablespoons of béchamel, add the filling and a little Emmental.

NextRepeat the layers and finish with the 2 tablespoons of crushed tomatoes, béchamel and Emmental.

Repeat the layers and finish with the 2 tablespoons of crushed tomatoes, béchamel and Emmental.

NextBake for 10 min at 180° (the oven should be preheated) and then grill for 15 min.

Done!