This one-pot spaghetti dinner comes together fast and delivers big comfort-food flavor. Perfect for busy weeknights when you want something satisfying with minimal cleanup.
Set the Instant Pot to saute mode and add the olive oil. Once hot, add the ground beef and break it apart with a wooden spoon. Cook for about 5 minutes until browned and no pink remains. Drain any excess grease if needed.
Add the diced onion and cook for 3 minutes until softened. Add the garlic, italian seasoning, salt, black pepper, and red pepper flakes. Stir and cook for 30 seconds until fragrant.
Pour in the water and scrape up any browned bits from the bottom of the pot. Add the spaghetti, fanning it out in a crisscross pattern so the noodles do not clump together. Press the pasta down gently so it is mostly submerged but do not stir.
Pour the marinara sauce evenly over the top of the pasta. Do not stir. Lock the lid, set the valve to sealing, and cook on high pressure for 8 minutes.
When the cook time is done, do a quick release by carefully turning the valve to venting. Once the pin drops, open the lid.
Stir everything together thoroughly, letting the residual heat thicken the sauce for about 2 minutes. The spaghetti will continue to absorb liquid as it sits. Top with grated parmesan cheese and fresh basil before serving.