1Sauté minced garlic in butter for 1 minute. Add sliced leeks and sauté for 2-3 minutes. Add zucchini and sauté for another 2-3 minutes.
2Add frozen spinach, broccoli, salt, pepper, and oregano. Sauté until veggies are tender and most of the liquid has evaporated. Set aside.
3In a pot, melt butter and add flour, whisking constantly for 1 minute. Gradually pour in milk, whisking until fully incorporated.
4Once all milk is added, turn heat to medium-high and whisk until the white sauce bubbles and thickens. Add salt, pepper, nutmeg, cayenne, and parmesan. Turn off heat.
5In a 9x13 inch dish, spread a thin layer of white sauce, then layer with noodles, half of the veggie mixture, parmesan cheese, and white sauce. Repeat layers.
6Top with remaining noodles, parmesan, mozzarella, and fresh basil.
7Cover with foil and bake for 50 minutes, then uncover and bake for 15 more minutes until golden brown and bubbly. Let it set for 5 minutes before enjoying.