Instructions

1. 1
   Put a thick-bottomed pot over medium-low heat. Add the oil and garlic, and stir until fragrant and blisters begin to form.
2. 2
   Add the tomatoes, and reduce the heat to low.
3. 3
   Simmer until it has a sauce consistency and has reduced to about ⅔ the original volume (about 1½ hours).
4. 4
   Turn off the heat and remove the garlic cloves to mash them with a fork. Add the garlic purée to the sauce.
5. 5
   Add salt to taste, cover, and let rest 30 minutes.
6. 6
   Pour the ricotta cheese onto a cheesecloth or tea towel in a strainer, and let drain for 30 minutes.
7. 7
   Combine the eggs and ricotta, and beat until creamy with a hand mixer.
8. 8
   Cover and reserve, ensuring it is at room temperature during assembly.
9. 9
   Thaw, drain, and press the liquid out of frozen spinach.
10. 10
    Reserve until ready to assemble.
11. 11
    Cook the pasta according to the manufacturer's directions, drain and place back into the pot with cold water.
12. 12
    Lay the sheets on a clean, wet tea towel and roll the cloth until ready to use.
13. 13
    Ladle sauce at the bottom of a 9x13-inch pan or dish and layer lasagna sheets.
14. 14
    Sparsely deposit spinach onto the noodles and apply cheese mixture with a rubber spatula.
15. 15
    Add more sauce and repeat the previous step until the pan is almost full and covered with a layer of lasagna.
16. 16
    Add sauce and cover with grated mozzarella.
17. 17
    Put the pan onto a tray and bake at 350°F for approximately 30 minutes, or to an internal temperature of 150°F.
18. 18
    Let rest for 15–20 minutes before serving.