Wash and chop the zucchini, spinach, bell peppers, and mushrooms into bite-sized pieces.

Set your Instant Pot to the sauté function and heat a splash of olive oil. Add the chopped mushrooms and bell peppers and sauté for about 5-7 minutes until tender.

Stir in zucchini and spinach, cooking for an additional 2-3 minutes until wilted. Add cream cheese and half the shredded cheese, mix until creamy.

Lock the lid onto the Instant Pot and set to pressure cook on high for 5 minutes.

Carefully perform a quick release of the steam. Stir the casserole to combine.

Preheat your oven to broil. Sprinkle remaining cheese on top and broil for about 3-5 minutes until bubbly and golden brown.

Allow to rest for a few minutes before serving. Scoop onto plates and enjoy!