Salmon lasagna / Lasagnes au saumon

Ingredients:
1 box of lasagna
500 ml plain milk
Grated cheese
Parmesan
olive oil
300 gr of diced salmon
2 tbS Plain flour
2 tbS Butter
Bunch of Spinach
1 big onion
3-4 garlic cloves
1 cup cream milk or sour cream
Salt and black pepper
1/2 ts Nutmeg