I suppose everyone has their preferences when it comes to lasagna. I like mine packed with veggies, but I don't want the vegetables to distract from the cheese. Which is how I wound up with a veg-cheese filling that blends puréed spinach, grated carrot, and chopped onion with mozzarella, parmesan, and ricotta.
I originally made this lasagna with hand-chopped fresh spinach, but when I got a food processor, I found that it was faster (and cheaper) to use frozen spinach -- there's no change in flavor, and a slight improvement in texture. I also use store-bought tomato sauce in this lasagna, although you can make your own if you want. It's a pretty simple, no-fuss recipe, but the result is respectable enough to serve guests.
9 lasagna noodles, cooked per package instructions
10 ounces frozen spinach, thawed
1 carrot, washed and grated
1 onion, washed and finely chopped (or grated)
1/2 teaspoon salt
black pepper to taste
15 ounces (approx. 1 and 3/4 cup) part-skim ricotta
8 ounces grated mozzarella cheese, divided
About 3 ounces grated parmesan cheese, divided
26 ounces store-bought tomato sauce (about 3 cups)
Preheat the oven to 375F.
Purée the spinach in a food processor.
Transfer the spinach into a large bowl, and slowly blend in the carrot, onion, egg, salt, pepper, nutmeg, and ricotta, along with 2/3 of the mozzarella and 1/2 of the parmesan. Set the veg-cheese mixture aside.
Pour about 1/3 of the tomato sauce into a 9 x 13 baking dish, so that the bottom of the dish is covered.
Top the tomato sauce with three of the lasagna noodles.
Cover the lasagna noodles with 1/2 of the veg-cheese mixture (spreading the mixture so that the noodles are evenly covered).
Top the veg-cheese mixture with three more of the lasagna noodles.
Pour another third of the tomato sauce over the lasagna noodles.
Use the rest of the veg-cheese mixture to cover the tomato sauce.
Top the veg-cheese mixture with the last three lasagna noodles.
Pour the last of the tomato sauce over the lasagna noodles.
Cover the baking dish with aluminum foil and bake for 35 minutes.
Remove the foil and add the remaining mozzarella and parmesan cheese.
Bake (uncovered) for another 10 minutes, or until the cheese has melted.
Remove the lasagna from the oven and let sit for 10 minutes.
(I get 9 generous servings -- any leftovers freeze nicely.)