Press SAUTE on the Instant Pot, and when it reads Hot, add the olive oil and onions, and sauté until onions are soft
Add ground beef and sausage, breaking up with a spatula, sea salt, garlic and pepper, and cook until no longer pink stirring continuously
Hit CANCEL, then add beef broth, and deglaze with spatula to remove any browned bits, if necessary.
Pour in marinara sauce, but do NOT stir. Then, place broken lasagna noodles on top
Place lid on pressure cooker, turn vent to Sealing position, and hit PRESSURE COOK for 5 minutes
Pot will take several minutes to reach pressure, then start counting down and cook for 5 minutes. After pot beeps, allow a 5 minute natural release, then turn knob to venting to quick release remaining pressure
When pin drops, remove lid, and stir. Then, gradually stir in heavy cream and mix until well combined
Serve topped with ricotta mixture and extra cheese, if desired