Mushroom, Spinach and Pesto Lasagna with Fontina Cheese
This inspired vegetarian lasagna, which features both pesto and marinara sauces, may take a while to assemble, but don’t be intimidated. Both of the sauces can be prepared days or even weeks in advance, and the results are worth it. The recipe will make more marinara sauce than you need, but leftovers can be kept for up to 2 months in the freezer and are great to have on hand for a quick weeknight meal.
For the pesto:
- 2 cups (2 oz./60 g) packed fresh basil leaves
- 2 garlic cloves
- 1/4 cup (1 1/2 oz./45 g) pine nuts, toasted
- 1/2 cup (4 fl. oz./125 ml) extra-virgin olive oil
- Kosher salt and freshly ground pepper
- 1/2 cup (2 oz./60 g) grated Parmesan cheese
For the marinara sauce:
- 2 Tbs. olive oil
- 1 small yellow onion, finely chopped
- 3 garlic cloves, minced
- 1 can (28 oz./875 g) crushed tomatoes
- Kosher salt and freshly ground pepper
- 1/2 tsp. dried oregano
For assembling the lasagna:
- 1/2 lb. (250 g) lasagna noodles
- 3 Tbs. plus 1 tsp. olive oil, plus more for greasing
- 4 garlic cloves, minced
- 1 lb. (500 g) button or cremini mushrooms, brushed clean and sliced
- 10 oz. (315 g) spinach leaves, tough stems removed
- 3 cups (24 oz./750 g) whole-milk ricotta cheese
- 1 egg, lightly beaten
- 1/2 lb. (250 g) fontina cheese, shredded
To the make the pesto, in a food processor or blender, combine the basil, garlic and pine nuts. Pulse until the ingredients are uniformly minced, scraping down the sides of the bowl or jar as needed.
With the machine running, slowly drizzle in the olive oil and process until smooth and well combined. Season with salt and pepper. Transfer the pesto to a bowl and stir in the cheese. Use immediately, or store in an airtight container in the refrigerator for up to 2 weeks or in the freezer for up to 2 months.
To make the marinara sauce, in a heavy saucepan over medium heat, warm the olive oil. Add the onion and sauté until translucent, about 5 minutes. Add the garlic and sauté just until soft, about 1 minute more.
Stir in the tomatoes with their juice and season with salt and pepper. Raise the heat to medium-high and bring to a boil. Reduce the heat to low, add the oregano and simmer for 15 minutes. Remove from the heat. Taste and adjust the seasoning.
Measure out 1 cup (8 fl. oz./250 ml) of the sauce to use in the lasagna, saving the remaining 2 cups (16 fl. oz./500 ml) for another use. If not using the sauce immediately, let the sauce cool completely before storing in an airtight container in the refrigerator for up to 2 weeks or in the freezer for up to 2 months.
Preheat an oven to 375°F (190°C).
To assemble the lasagna, bring a large pot of generously salted water to a boil over high heat. Add the lasagna noodles and cook according to the package instructions. Drain well and arrange the noodles in a single layer on an oiled baking sheet. Set aside.
Warm the 3 Tbs. olive oil in a fry pan over medium-high heat. Add the garlic and mushrooms, season well with salt and pepper, and cook, stirring often, until the mushrooms are golden brown and soft but still hold their shape, about 4 minutes. Transfer the mushroom mixture to a plate. Do not wipe the pan clean. In the same fry pan over medium-high heat, warm the 1 tsp. olive oil. Add the spinach, season well with salt and pepper, and sauté until just wilted, about 3 minutes. Drain well and set aside.
In a bowl, stir together the ricotta and egg and season well with salt and pepper. Set aside. To assemble the lasagna, coat a 9-by-13-inch (23-by-33-cm) baking dish with nonstick cooking spray and arrange one-third of the noodles on the bottom. Top the noodle layer with half of the ricotta mixture (dollop it evenly), all of the pesto, half of the mushrooms, half of the spinach and one-third of the fontina. Arrange another layer of noodles over the filling and top with the remaining ricotta mixture, all of the marinara, the remaining mushrooms and spinach, and another one-third of the fontina. Place the final layer of noodles on top and scatter the remaining fontina evenly on top.
Bake until the sauce is bubbling, about 40 minutes. Let cool slightly and serve. Serves 8 to 10.
Adapted from Williams-Sonoma Pasta Night, by Kate McMillan (Weldon Owen, 2014)