Make the marinara sauce by sauteeing the onion for 3 minutes. Add the garlic until fragrant and then add the can of tomatoes. Let it sautee for 5 minutes
Set Marinara sauce aside and brown the sausage for 2-3 minutes. Once browned turned the sautee option off and add the marinara sauce to the pot
Add the broth or water.
Break the lasagna sheets in ⅓ pieces and add to the soup
Place lid on Instant Pot and turn the knob to the sealed position and cook on High Pressure for 4 minutes (or half the time your lasagna noodles box specifies to cook them for)