Preheat your oven to 375°F (190°C).

If using regular lasagna noodles, bring a pot of salted water to a boil and cook the lasagna noodles until al dente according to package instructions. Drain and set aside. If using no-boil sheets, skip this step.

Heat the olive oil in a pan over medium heat. Add the zucchini slices and sauté for about 3-4 minutes until slightly tender. Add the spinach and cook for another 2 minutes until wilted. Season with salt and pepper to taste. Remove from heat.

In a 9x9 inch baking dish, spread a small amount of marinara sauce at the bottom to prevent sticking. Place one lasagna noodle sheet over the sauce.

Spread a portion of ricotta cheese over the noodle, followed by a layer of the spinach and zucchini mixture. Sprinkle some shredded mozzarella on top and a little more marinara sauce.

Repeat the layering process for the remaining sheets, finishing with a top layer of marinara sauce and a generous sprinkle of shredded mozzarella cheese.

Cover the baking dish with aluminum foil and bake in the preheated oven for 20 minutes. Remove the foil and bake for another 10 minutes, or until the cheese on top is bubbly and golden brown.

While the lasagna is baking, prepare the side salad. In a large bowl, combine the mixed salad greens, add a drizzle of olive oil, and season with salt and pepper to taste. Toss gently.

Remove the lasagna from the oven and let it cool for a few minutes before serving. Serve with the fresh mixed salad on the side.