Chop the veggies first, then cook your onions, garlic, and ground beef in the steel pot using the saute setting. Grab your pasta and tomatoes once you start cooking.
Add your crushed or strained tomatoes and dried herbs and stir for a few minutes. If you're using fresh herbs, wait to add them after your spaghetti is complete.
It's essential to have this base of ingredients and liquid before adding your spaghetti noodles to prevent them from sitting at the bottom of the pot and burning.
Like a layered dish, add in your dry, broken spaghetti, water or chicken stock, and diced tomatoes. Close your Instant Pot and press the pressure cook setting.
You should have a full-blown spaghetti meal in under 10 minutes. During that window of uninterrupted cooking time, you can steam some veggies on the stove and set the table.