Add the chopped onion and minced garlic to the pot and cook until softened, about 3-5 minutes.
Stir in the marinara sauce, beef broth, Italian seasoning, salt, and pepper.
Place the uncooked spaghetti noodles on top of the sauce mixture. You can layer them in a criss-cross pattern to help prevent clumping.
Secure the lid and set the valve to the sealing position.
Cook on High Pressure for 8 minutes.
Once the cooking cycle is complete, perform a Quick Release of the pressure.
Carefully remove the lid. Stir the spaghetti to ensure it is fully mixed with the sauce.
Serve immediately, topped with Parmesan cheese if desired.
Notes
To prevent the ‘burn’ notice with tomato-based sauces, ensure you have enough liquid (broth) and that the sauce is not directly touching the bottom of the pot if possible. Layering the pasta on top of the sauce helps with this.
For a 6-quart Instant Pot, the liquid ratios and cook times are generally the same. For an 8-quart model, you may need to slightly increase the liquid or cook time, though 8 minutes on High Pressure usually works well for both.
To reheat leftovers, add a splash of water or broth to the pasta in a microwave-safe dish and heat until warmed through.
This recipe can be doubled in an 8-quart Instant Pot, but ensure you maintain the correct liquid-to-pasta ratio and adjust cook time if necessary.
Consider this a great option for meal planning, similar to what you might find with some meal delivery companies.