Turn the Instant Pot to ‘Saute mode.’ Once it displays ‘hot,’ add oil to the insert. Add garlic and sauté for a minute or until fragrant.
Add chopped onions. Cook for 2-3 minutes until the onions are soft and translucent.
Stir in celery, carrots, great northern beans, kidney beans, chopped tomatoes, Italian dressing, macaroni pasta, bay leaves, salt, and red pepper flakes.
Pour in vegetable stock. Mix until everything is combined. Don’t forget to deglaze the base of the insert. PROTIP – Deglazing the insert removes all the brown bits stuck to the base. Scrape everything from the base to prevent the burn message. Turn the Instant Pot off. Close the lid and seal the pot. Press the Manual or pressure cook button and cook the Instant Pot Minestrone Soup for 4 minutes on HIGH.PROTIP – It will take somewhere about 10 minutes for the pressure to build then the actual cooking time will start. Once the cooking time has elapsed, allow the pressure to release naturally for 10 minutes, and turn the steam valve to the venting position to release the remaining pressure. When the pin drops, carefully open the lid.
Remove the bay leaves from the soup and discard.
Add zucchini and spinach leaves. Give it a good stir. PROTIP – Zucchini and spinach leaves take less cooking time, so always add them at last. Turn the Instant Pot to ‘Saute mode.’ Allow the minestrone soup to simmer for 2-3 minutes, stirring periodically.PROTIP – Don’t simmer for long; our purpose is to soften the vegetables. If simmered for a long time, the pasta will soak up all the liquid and become mushy. Finally, add the chopped parsley leaves and serve warm.