Using the display panel select the SAUTÉ function and adjust to MORE . Add sausage, ground beef, onions and garlic to the Instant Pot.
Brown the meat until no pink remains, using a wooden spoon to break up the meat into small pieces. Drain and discard liquids.
Add thyme, oregano, rosemary, bay leaf, undrained tomatoes, tomato sauce and warmed broth and stir.
Add pasta. Do not stir, but ensure all pasta is submerged.
Turn the pot off by selecting CANCEL , then secure the lid, making sure the vent is closed.
Using the display panel select the MANUAL or PRESSURE COOK function*. Use the +/- keys and program the Instant Pot for 5 minutes. (If using lasagna noodles, check the cook time on the package and divide it by two and round up to the next whole minute to get to the correct cooking time. )
When the time is up, let the pressure naturally release for 5 minutes, then quick-release the remaining pressure.
Meanwhile, in a small bowl, mix Cheese Mixture ingredients.
Ladle soup into serving bowl, top with 1 - 2 tbsp of shredded mozzarella and a dollop of the cheese mixture. Garnish with basil ribbons.
Notes
The MANUAL and PRESSURE COOK buttons are interchangeable.