Prep the vegetables by washing and chopping zucchini, bell peppers, mushrooms, onion, and garlic.

In the Instant Pot, select the sauté function and add olive oil. Stir in the onion and garlic, cooking for 2-3 minutes until fragrant.

Add zucchini, bell peppers, mushrooms, and spinach to the pot. Sauté for 5-7 minutes until softened.

In a separate bowl, whisk together eggs, cheese, and spices. Fold this mixture into the sautéed veggies.

Seal the Instant Pot lid and select the Manual or Pressure Cook setting for 5 minutes on high pressure.

Once cooking is complete, carefully perform a quick release of pressure and check doneness.

Allow the casserole to cool slightly before slicing and serve warm with salad or bread.