Fill a large pot with water and add 1/2 teaspoon of salt and bring to a boil. 

When the pasta has come to a boil add the lasagna noodles and stir periodically so the noodles do not stick together. 

When the noodles still have a bite to them (a little more bite than al dente) strain the water from the noodles and drizzle the noodles with olive oil. Lay the noodles out flat and set aside. 

Next, heat a large skillet over medium/high heat and add olive oil. 

When the olive oil is fragrant add the onions and ½ teaspoon of salt to the pan and sauté the onions until they are translucent (3-4 minutes). 

Add the garlic to the onions and sauté for 1-2 minutes. 

Then, add the diced tomatoes and spinach to the pan, stir, and bring the tomatoes to a boil. Turn heat to low, cover the pan, and cook the spinach and tomatoes until the spinach is wilted. Remove from the heat and set aside. 

Preheat the oven to 375ºF and generously spray a 9x13-inch casserole dish with non-stick cooking spray. 

Add butter to sauce pan and when the butter is melted add the flour to the butter and whisk them together until they form a paste. 

Slowly pour the milk into the saucepan and continue to whisk all the ingredients together until the milk thickens. 

After the sauce is thick, remove from the heat and add 1 cup shredded cheddar cheese and 1 cup shredded parmesan cheese to the thickened milk and stir until the cheese has melted. 

Finally, add the salt, pepper, garlic, powder, and fresh thyme to the Alfredo sauce and stir until combined. Set aside. 

Next, add one layer of noodles to the bottom of the casserole dish, scoop 1/3 cup of the Alfredo sauce and a 1/3 cup of the vegetable mixture to the top of the noodles and spread it evenly over the noodles. Add 1/3 cup of shredded chicken to the top of the sauce. Repeat until all the noodles, sauce, vegetable mixture, and chicken are gone (make sure the last layer is Alfredo sauce and the vegetable mixture). 

Place the lasagna into the oven and bake at 375ºF for 25 minutes, uncovered. 

Remove the lasagna from the oven and sprinkle on 1 cup of mozzarella cheese and the remaining ½ cup parmesan cheese to the top of the lasagna.

Place the lasagna back in the oven and bake for an additional 10-12 minutes or until the cheese is golden brown. 

Remove from the oven and enjoy.