Preheat oven to 350 F.

In a large pot, heat oil over medium heat. Add onions, celery, carrots and sauté for 6-7 minutes until soft and slightly golden. Add in tomato paste and sauté for an additional minute. add in sauce and cook until sausage has browned, about 5-6 minutes. Stir in spinach until slightly will wilted and add in strained tomatoes. Sure water to rinse tomato jar or can of leftover sauce and pour into pot. Season with salt an pepper. You can adjust the seasoning wants sauce is finished as I find using sausage meat tends to be already seasoned. Bring sauce to boil and reduce to simmer. Leave uncovered and simmer for 20 minutes.

Cover the bottom of a 13x9 oven safe dish with 1 cup of sauce. Tope with lasagna noodles to cover. Add sauce and sprinkle top with 1/2 cup of mozzarella cheese. Repeat with additional 6 layers, you should end up with the sauce as your top layer. Sprinkle top with remaining cup of mozzarella cheese and the parmigiano. Cover with foil and bake for 45-50 minutes. Remove foil and turn oven to broil and bake for 2-3 minutes until cheese is slightly golden and bubbly. Be careful not to burn it. Remove from oven, cover with the foil and let set for 5-7 minutes. Top with fresh basil before serving.