In a casserole filled with boiling salted water, cook lasagna pasta al dente. Drain.
Meanwhile, melt butter at medium heat in a small casserole. Cook leeks for 2 to 3 minutes.
Add flour and cook for 1 to 2 minutes while stirring.
Gradually add warm milk while whisking. Bring to a boil, then simmer for 3 to 5 minutes at low heat. If desired, add dill.
Pour a bit of sauce on a baking plate 33 cm x 23 cm (13 inches x 9 inches). Cover with 3 lasagna noodles, then a quarter of the remaining sauce and a third of the smoked salmon. Repeat two times. Cover with the remaining pasta, then with the remaining sauce. Garnish with cheese.
Oven bake for 18 to 20 minutes.
Set the oven on a broil and cook for 2 to 3 minutes, until cheese is roasted.
Did you know that...
Our sliced leeks are washed and ready to cook. All you have to do is open the bag!