In the pressure cooker, heat the oil on the saute function (medium heat). Add the onions and green peppers, stirring regularly, until they begin to soften.
Add the ground beef and saute, breaking it apart as you do. Once the meat is cooked through, drain off any excess fat.
Add the salt, pepper, basil, oregano, parsley, garlic powder, onion powder, Worcestershire and beef stock, and stir, making sure to scrape the bottom of the crock to get any cooked-on bits.
Once everything is well combined, add the pasta to the pressure cooker, and stir again to submerge the noodles.
Seal the pressure cooker and cook on high pressure for 4 minutes. Manually release the pressure, add the cheese and stir until it is melted and well combined.