The Instant Pot is the quickest, mess-free way to have lasagna on the table in no time! Plus there's easy clean-up and no oven required :)
Set your Instant Pot to sauté, and brown the beef with the onion, adding in the garlic and Italian seasoning.
Once your beef is browned, transfer the ground beef to a separate bowl using a slotted spoon.
Pour two cups of water into the pot, and scrape the bottom with a spatula, lifting up all those flavorful, stuck-on bits.
Add about a third of the ground beef back into the pot with the water, and cover with lasagna noodles.
Cover the noodles with some of the marinara sauce, and another layer of beef, followed by half of the ricotta mixture.
Top this with a layer of spinach and one more noodle layer. Then repeat with the remaining fillings.
Close the lid and set the Instant Pot valve to seal. Cook on high pressure for 6 minutes.
Cover the top of the lasagna with a layer of shredded mozzarella cheese. Then close the lid, and let it melt.
Once the mozzarella is nice and melty, take the lid off again and serve!