Mixricotta cheese, spinach, mozzarella cheese, oregano, and salt together till they are well combined.
Assembling the lasagna
Line the springform pan with parchment paper.
Pour 1 cup of pasta sauce into the parchment paper-lined pan.
Place the lasagne over it in a single layer. Use enough pasta to cover the sauce.
Top the lasagne with half of the ricotta mixture.
Repeat the layers starting with pasta sauce, lasagne, then the ricotta mixture until the pan is almost full to the brim. If using a 7-inch springform pan, you should be able to repeat the layers twice. Finish with a final layer of marinara sauce.
Cover the pan with foil.
Add 1.5 cups of water to the base of the Instant Pot.
Place the springform pan carefully on a trivet and lower it into the inner pot of the Instant Pot.
Cover the Instant Pot and pressure cook on high for 30 minutes.
Once the cooking cycle is complete, wait for 10 minutes before releasing pressure.
Carefully remove the springform pan from the Instant Pot.
Remove the foil and top it with cheese. Cover with foil and in about 5-10 minutes, the cheese should have melted. Alternatively, broil it for 2-3 minutes until the cheese has melted.
Let the lasagna rest for 15-20 minutes. Garnish it with freshly chopped parsley leaves.
Slide a knife around the edges of the lasagna to loosen it. If using a springform pan, unhinge the clasp and remove the sides of the pan.
Cut the lasagna into slices and serve immediately.
Notes
Recipe notes and tips
Let it rest - After broiling allow the lasagna to cool and rest for 15 minutes in the springform pan. This will help the lasagna keep its shape and make it easier for cutting.
Ingredient Swaps
Pasta - Swap the no-boil lasagne for traditional lasagne pasta. I would suggest breaking the lasagne in half and then soaking them in hot water for 15-20 minutes before using them in the lasagna.
Spinach - If fresh spinach is not available, you can easily swap it for kale or frozen spinach. Thaw and drain the frozen spinach before using it to prevent adding additional moisture to the ricotta filling.
How to prep ahead
If you want to save some time during the week, here are a few ways you can prep ahead for a quicker weeknight dinner.
Make the whole lasagna - This vegetarian lasagna can be made and stored in the refrigerator for up to 2 days before you plan to bake.
Freeze lasagna- Follow the directions for making the entire lasagna and allow it to cool completely before storing it in a freezer-safe container. To serve, let it thaw overnight and reheat in a microwave until heated through (~8-10 minutes).
How to store
Keep this easy lasagna in the refrigerator in an airtight container after baking for up to 3-5 days. Store in a freezer-safe container for up to 3 months in the freezer.