1 pound whole-wheat lasagna noodles
3 tablespoons olive oil
1 large yellow onion, chopped
2 cloves garlic, minced
2 cups mushrooms, chopped
1 red bell pepper, chopped
2 small zucchini, sliced into rounds
2 small yellow squash, sliced into rounds
4 tablespoons butter
1/4 cup all-purpose flour
2 cups milk
3/4 cup grated Parmesan cheese, divided
Salt and pepper
10 ounces fresh or frozen spinach, steamed, squeezed dry and chopped
1 15-ounce container ricotta cheese
1/3 cup store-bought pesto, or Buddy's Master Pesto recipe
1 pound mozzarella cheese (the non water-packed kind), torn into pieces
Preheat oven to 375 degree F. Butter a 9 x 13" baking dish.
Bring a pot of salted water to a boil. Add lasagna noodles and cook for 8 to 10 minutes, or until al dente. Drain and let cool.
Heat the olive oil in a large skillet over medium-high heat. When the oil is hot, add the onions and garlic with a pinch of salt and stir to coat with the oil. Cook, stirring, for about 30 seconds. Add the mushrooms, red pepper, zucchini and yellow squash with another pinch of salt. Reduce heat to medium and sauté for 8 to 10 minutes until the vegetables have softened and exuded their juices.
Heat the milk in a saucepan over medium to low heat to avoid scalding. Then, heat the butter in a medium saucepan. Whisk in the flour to the butter and cook for 1 to 2 minutes, to remove the raw flour taste and completely melt the butter. Gradually whisk in heated milk until well blended. Bring to a boil over medium heat. Cook 5 minutes, or until thick, stirring constantly.
Stir in 1/2 cup Parmesan cheese and whisk until smooth. Remove from heat and stir in the chopped spinach. Season to taste with salt and pepper. Set aside 1/2 cup of the spinach mixture for top of the lasagna.
In a small bowl combine the ricotta and the pesto.
Spread a thin layer of spinach mixture in the bottom of prepared pan. Add a layer of noodles, 1/3 of the ricotta mixture, 1/3 of the vegetables, 1/3 of the spinach mixture, 1/4 of the mozzarella. Repeat this layering two more times. Finish with a top layer of noodles, the reserved spinach mixture, the remaining mozzarella and the 1/4 cup of Parmesan cheese.
Cover with foil and bake in preheated oven for 20 minutes. Remove foil and continue to bake for an additional 20 minutes or until lightly browned on top. Cool for approximately 10-20 minutes before serving.