Press saute mode in your instant pot and add the olive oil. When the oil gets hot add the serrano chili and onion and cook for 3 minutes. Add garlic and saute for another 30 seconds. Now add the red chili flakes and oregano and saute for 15 seconds.
Add the veggies – carrot, bell pepper and zucchini and saute for two minutes.
Now add the broken lasagna noodles, tomato sauce, vegetable broth, water, bay leaf, and chopped parsley. Taste the broth and check if you need to add salt. If so add it and stir well making sure nothing is sticking to the bottom of the pan. Also make sure all the pasta is under the liquid.
Hit cancel, secure the lid and adjust the vent to sealing position. Cook on high for 4 minutes and wait for 5 minutes (not more than that) to release the pressure.
Add spinach and ricotta cheese and mix it. Press saute mode and cook for 2-3 minutes. Taste and adjust salt if required. Let the soup rest for five to ten minutes before serving.
Serve the lasagna soup topped with parmesan cheese, chili flakes, parsley or basil and a drizzle of olive oil. The soup will get thick with time, add some hot water to thin it out.