Preheat the oven to 350 degrees F.
Lightly grease a 9/13 baking dish with melted butter or olive oil. I like to use a glass baking dish/casserole dish, but a steel/no-stick dish or ceramic dish will also work well. Prepare your noodles. If you are making homemade pasta, make the noodles according to the recipe and set aside to dry while you prepare the rest of the lasagna. If you are using regular uncooked lasagna noodles, boil them according to package instructions, rinse them with cold water, and set them aside till ready to use. But if you are using oven-ready noodles, you don't need to do anything to prep them.
In a large bowl, combine the broccoli florets, shredded carrots, sliced peppers, pesto, and sea salt. Toss to combine, making sure that all the veggies are coated in the salt and pesto. Set aside.
In a medium bowl, combine the ricotta cheese, grated parmesan cheese, parsley, and egg, stir to combine, and set aside.
In a saucepan over medium heat, melt the butter and add the minced garlic, cooking for 1-2 minutes, or until the garlic is soft and fragrant, stirring constantly.
Add the flour and whisk to combine.
Finally, add the milk, and bring the mixture to a boil, whisking constantly, Whisk for 1-3 minutes or until the sauce is smooth and thickened. The sauce should be thick enough to coat the back of a spoon.
Spread a thin layer of white sauce on the bottom of your prepared pan. Place 3 lasagna noodles on top of it.
Scoop half the cheese mixture on top of the noodles and carefully spread it over the noodles with a spatula. Add another layer of lasagna noodles and half of the vegetable mixture and spread it out as best you can.
Sprinkle 1 cup of the mozzarella cheese over the veggies. Carefully pour half of the white sauce over the cheese and spread it out as best you can.
Repeat the layering process, noodles, cheese mixture, noodles, veggies, cheese, and sauce. You should have 4 layers of noodles, 2 layers of the cheese mixture, 2 layers of the vegetable mixture, and 2 layers of mozzarella cheese. The sauce should be gone and there should be 1 cup of cheese left.
Sprinkle the remaining cup of mozzarella cheese over the top of the lasagna, and place the pan in the preheated oven.
Bake uncovered for 35-40 minutes, or until the lasagna is hot and bubbly and the cheese is melted. Allow the lasagna to cool for 10 minutes before serving.
Serve with a side salad and crusty bread, enjoy!