1 28oz. can crushed tomatoes with the juice or 1 ¾ pound of fresh tomatoes — peeled, seeded and diced
Salt and ground fresh black pepper to taste
1 tbsp chopped fresh basil
3 cups spinach
15 oz part-skim ricotta
1 large egg
1/2 cup freshly grated Parmesan cheese
4 medium zucchini — sliced 1/8" thick
16 oz part-skim mozzarella cheese — shredded
1/2 tsp parsley — chopped
In a saucepan, heat olive oil over medium heat.
Add onions and cook 4-5 minutes until they are soft and golden.
Add garlic and sauté, being careful not to burn.
Add tomato paste and stir well. Add crushed tomatoes, including the juice in case you are using tomato cans.
Add salt and ground fresh black pepper.
Cover and bring to a low simmer for 25-30 minutes.
Finally, remove from the heat and add fresh basil, spinach and stir well.
Adjust the seasoning if you think it is necessary.
Preheat oven to 375°.
Arrange the zucchini slices in a single layer on a baking sheet and coat it with cooking oil spray. Broil for 5-8 minutes. Remove from the oven. Wait about 5 minutes to remove any excess moisture with paper towels if you think it's necessary. (This part is very important to avoid the lasagna to become soupy.)
In a medium bowl mix ricotta cheese, parmesan cheese, and an egg. Stir well.
In a 9x12 casserole spread some tomato spinach sauce on the bottom.
Layer 5 or 6 zucchini slices to cover.
Place some of the ricotta cheese mixture and top with the mozzarella cheese. Repeat the layers until all your ingredients are all used up.
Top with sauce and mozzarella.
Cover the casserole dish with aluminum foil and bake for 30 minutes covered and 10-15 minutes uncovered.
Let stand about 10 minutes before serving. Garnish with parsley.