caramelized onion lasagna with gorgonzola & spinach

Serves 9

ingredients

8 ounces lasagna noodles (I use no-boil noodles)

caramelized onion filling

• 4 tablespoons extra-virgin olive oil
• 4 large sweet onions, thinly sliced (about 10 cups)
• 4 large portobello mushroom caps, gills removed (use a spoon to scrape out), diced
• 1/2 cup red wine
• 1 teaspoon salt

  

• Freshly ground pepper, to taste

spinach & cheese filling

• 4 cups baby spinach (1 bag)
  
• 3 cups nonfat ricotta cheese
• 3/4 cup chopped fresh basil
• 1/2 cup grated Parmesan cheese
• 1 tablespoon red pepper flakes
• 1 tablespoon garlic powder
• 1 teaspoon salt
  

  

white sauce & topping

• 3 tablespoons extra-virgin olive oil
• 4 tablespoons all-purpose flour
• 2 1/2 cups skim milk
• 1 teaspoon salt
• 3 ounces crumbled Gorgonzola cheese
• 1 1/2 cups shredded mozzarella cheese
  
• 1/2 cup chopped fresh basil

preparation

1. To prepare onion filling: Heat 4 tablespoons oil in a large skillet over medium heat. Add onions and cook, stirring frequently, until golden brown and very soft, about 30-40 minutes (If they begin to stick, add water 1/4 cup at a time to release them and prevent burning). Add mushrooms and cook, stirring, until mushrooms just begin to soften (about 3 minutes). Add wine and 1 teaspoon salt and continue cooking until most of the liquid is absorbed, 2 to 3 minutes. Remove from heat; stir in pepper.
2. To prepare spinach filling: Place spinach, ricotta, basil, Parmesan cheese, red pepper flakes, garlic powder and 1 teaspoon salt in a food processor; process until smooth.
3. To prepare white sauce: Heat 3 tablespoons oil in a medium saucepan over medium-high heat. Add flour and stir until bubbling, about 30 seconds. Gradually whisk in milk and 1 teaspoon salt; bring to a boil, whisking constantly. Cook, whisking, until the sauce has the consistency of thick gravy, about 1 minute. Add Gorgonzola and gently whisk until melted. Remove from the heat (sauce will continue to thicken as it sits).
4. To assemble lasagna: Preheat oven to 375°F. Coat a 9-by-13-inch baking pan with cooking spray.
5. Spread 1/2 cup white sauce in the prepared pan. Place a layer of noodles over the sauce. Spread half of the spinach filling over the noodles and top with one-third of the onion filling. Evenly spread 1/2 cup white sauce and 1/2 cup of mozzarella over the onions. Repeat with another layer of noodles, the remaining spinach filling, half the remaining onion filling, half the remaining white sauce and 1/2 cup of mozzarella. To finish, top with a third layer of noodles, spread the remaining onion filling over the noodles and then spread or dollop the remaining white sauce on top, and sprinkle with remaining mozzarella.
6. Bake until hot and bubbling, about 30 minutes. Let rest for 5 minutes before serving and sprinkle with fresh basil (optional).