Push SAUTE button on the Instant Pot. Once it is hot (it will only take a few minutes), cook and stir Italian sausage until brown. (You could also do this step on the stove top, but it’s just as easy to do it in the Instant Pot)
Add onions and mushrooms; saute until onions are clear.
Stir in spaghetti sauce, and heat through. Pour mixture into a bowl and set aside. Rinse out your pot.
In a medium size bowl, combine cottage cheese, ricotta cheese, grated Parmesan cheese, and eggs.
Spread a thin layer of the meat sauce in the bottom of a round 7-Inch Springform pan.
Layer with 1/2 of the uncooked lasagna noodles, breaking the noodles so they cover all the sauce. Then add 1/2 of cheese mixture, 3/4 cup mozzarella cheese, and 1/2 of the meat sauce. Continue layering until all ingredients are used or until your springform pan is filled to the top.
Cover pan with aluminum foil.
Place a trivet in the bottom of the Instant Pot. Add 1 cup of water on top of the trivet. Gently place your foil wrapped lasagna on top of the trivet.
Push the PRESSURE COOK or MANUAL and set the timer for 24 minutes.
When it is done, let it release on its own for a few minutes then turn the knob to VENTING to release all of the pressure.
When the pressure is out, remove the lid and take out the lasagna.
Add 1/2 cup of mozzarella cheese and broil in the oven for 2 minutes until the cheese it bubbly on top.
Let it cool for at least 10 minutes before serving.