• Preheat oven to 350 degrees Fahrenheit
• Place salmon in a sheet pan lined with aluminum foil
• Season the salmon with olive oil, salt, and pepper
• Bake for 16 minutes (salmon will be a tad underbaked)
• Remove from the oven and flake into large chunks with a fork
• Meanwhile steam asparagus for 2-3 minutes

For Bechamel

• Warm the milk in the microwave
• In a saucepan, melt the butter over medium-low heat
• When the butter is melted, add the flour and whisk until everything is incorporated and the flour is cooked (about 45 seconds to 1 minute)
• Add the warm milk and whisk vigorously to avoid lumps
• Keep whisking until the sauce starts getting thick and creamy
• Add the dill
• When the sauce boils, remove from heat and add the dijon mustard, lemon juice, gruyere cheese, salt, and pepper. Mix until combined and check for seasoning

Assembly

• Place 3 sheets of lasagna noodles on the bottom of a rectangular 9x13" baking dish
• Add 1/3 of the sauce and place the steamed asparagus in a single layer
• Top with 1/2 cup of mozzarella cheese, salt, and pepper
• Top with 3 more lasagna noodles
• Add 1/3 of the sauce
• Place all the salmon making sure it covers the whole layer
• Top with 1/2 cup of mozzarella cheese
• Top with 3 more lasagna noodles
• Add the rest of the sauce and spread to cover the whole surface
• Add 1 cup of mozzarella cheese and gruyere
• Bake for 30 minutes
• Broil for 2-3 minutes or until the top has browned
• Remove from the oven and let it sit for 15 minutes before cutting
• Enjoy!