Preheat oven to 400 degrees F. Heat 1 tablespoon oil in large skillet over medium heat. Add salmon and cook, stirring until opaque, 1 to 2 minutes. Transfer to medium bowl.

Add the remaining 1 tablespoon oil to skillet over medium heat. Add zucchini, sprinkle with ½ teaspoon salt and cook until tender, 5 to 7 minutes. Transfer to bowl with salmon

In medium bowl, combine creme fraiche, lemon juice, nutmeg, remaining ½ teaspoon salt and pepper.

Spread 1/3 creme fraiche mixture over bottom of 9x9-inch baking dish. Top with layer of lasagna sheets, breaking them as necessary to cover pan. Spread 1/2 salmon mixture over lasagna sheets. Add another layer of lasagna sheets, another 1/3 creme fraiche mixture and remaining salmon mixture. Top with a third layer of lasagna sheets, remaining creme fraiche mixture and shredded mozzarella.

Cover and bake 30 minutes. Remove cover and bake another 10 or so minutes, until top is crispy and melty. Cool 5 to 10 minutes in the pan before slicing and serving.