Wash and chop your zucchini and bell peppers into bite-sized pieces. Dice the onion and mince the garlic.

Select the sauté function on your Instant Pot. Heat olive oil and sauté onions and garlic until fragrant, about 3-5 minutes.

Add the chopped zucchini, bell peppers, and diced tomatoes. Stir in the fresh spinach until wilted.

Sprinkle salt, pepper, and any preferred herbs like Italian seasoning into the pot. Stir well to combine.

Secure the Instant Pot lid, set the valve to sealing, and cook on high pressure for 5 minutes. Allow natural pressure release for 10 minutes.

Open the lid and stir in your choice of cheese. Allow to melt for 2-3 minutes.