Add the oil and when it is hot add the onion, carrot, celery, bay leaf, garlic and bacon. Sauté slowly until the vegetables have softened and the bacon has cooked through.
Raise the temperature of the Instant Pot by canceling the Sauté function then resetting it to Sauté “more.” Add the meat and quickly brown it in the pot, stirring constantly to break it up.
Cancel the Sauté function. Remove the bay leaf and add the rest of the ingredients. Close the lid and turn the valve to “sealing”. Set the Instant Pot to high pressure cooking by pressing “Manual” and adjust cooking time to 20 minutes.
Once cooked either do quick pressure release if the sauce is needed immediately, otherwise allow the pressure to release naturally.
Serve with spaghetti or tagliatelle and a generous sprinkling of grated parmesan.