Begin by finely chopping the onion, carrots, and celery, ensuring a uniform size for quick cooking. Mince several cloves of garlic and slice the zucchini into thick coins.

Set your Instant Pot to the sauté mode and add a splash of olive oil, heating for a minute. Toss in the onions, garlic, carrots, and celery, stirring frequently for about 5 minutes until softened.

Pour in the vegetable broth, stirring to deglaze the pot. Add the canned tomatoes, dried oregano, bay leaves, and zucchini. Season with salt and pepper to taste.

Secure the lid, set the valve to sealing, and select manual pressure or soup setting for 7 minutes.

Once done, switch the valve to venting for a quick release. Stir in the spinach or kale, letting it wilt.

Taste and adjust seasoning as needed. Ladle the soup into bowls and serve hot, removing bay leaves.