In the opened pressure cooker, add the oil and heat at medium until it just begins to smoke. Add the onions, ground beef, salt, and pepper and continue cooking until the onions become transluscent and the beef has browned.
Add the pasta sauce and water to the beef and onions. Stir and remove from heat into a large bowl.
In another bowl, mix the ricotta, eggs, parmesan, garlic, seasoning, and some more salt and pepper as desired.
Fill the bottom of the cooled pressure cooker with 1/4 inch of water. Layer with a fifth of the beef and sauce into the bottom then top with noodles. Cover the noodles with a third of the cheese. Cover the cheese with another layer of sauce, then noodles. Repeat until all layers have been used. The final layer should be noodles topped with sauce.
Lock the lid and bring to high pressure. Reduce heat to level to maintain high pressure and cook for 7 minutes. After 7 minutes, quick release pressure and sprinkle with remaining cheese. Cover and allow to rest for 10 minutes.
Serve from the pressure cooker pot with some crusty bread.