I used zucchinis instead of pasta for the layers. For this you'll have to slice the zucchinis very thin, distribute the slices on a paper towel and add some salt to release the water from zucchinis, this have to rest for at least half an hour. Then you can squeeze them to realease more water, if you dont do this its gonna be a juicy lasagna. After this you can use zucchinis the same way you use pasta.

In a large pan over medium heat, add onions, chopped tomatoes, salt, pepper, oregano and meat. Cook until the meat is brown and ready, then add tomato sauce.

For the white sauce, bring milk to boil add salt & pepper to taste, and in a cup dissolve the cornstarch with half cup of milk. When milk is boiling (constantly stirring) add corstarch previously dissolved. Stir until thickened, keep cooking for 3 minutes. And its ready.

Alternate zucchinis, meat sauce and white.sauce as you like, as the same way you make a traditional lasagna. Cook in the oven for 45 minutes.