Preheat the oven to 400°F.
Melt butter in a large saucepan over medium heat. Sprinkle with flour and whisk into butter until smooth. Continue stirring and cook for 5-7 minutes or until roux turns a light golden color.
Increase heat to medium-high and slowly whisk in milk until thickened and combined. Gently simmer over medium-low heat for 10-20 minutes until raw flour taste has disappeared and a smooth sauce results at desired thickness.
Season with salt, pepper and nutmeg.
In a very large skillet, heat olive oil. Add spinach and continue to toss and stir until wilted. Do not over cook. Remove from heat and set aside.
Meanwhile, bring a pot of lightly salted water to a boil. Add broccoli and cook 2-3 minutes until just tender-crisp. Do not over cook. Drain broccoli in a colander and add to a large mixing bowl.
Chop broccoli into rustic chunks. Add spinach and stir to combine. Season with salt and pepper to taste.
Add a light layer of bechamel sauce to the bottom of a 9x13” casserole dish.
Next add a layer of the spinach-broccoli mixture, followed by 3 lasagna noodles.
Top the noodles with a layer of bechamel sauce, spinach-broccoli mixture, ricotta and mozzarella. Add 3 more noodles and repeat the layers as before finishing with mozzarella.
Bake uncovered for 20 minutes. Serve with a fresh green salad and freshly grated parmesan cheese. Enjoy!