Turn on the Instant Pot and select the sauté function.
Add olive oil and heat for 1 minute.
Add chopped onion and sauté until translucent, about 5 minutes.
Stir in minced garlic and cook for an additional 1 minute.
Add diced carrots and celery, sautéing for 3-4 minutes.
Pour in the broth and add diced tomatoes.
Season with thyme, salt, and pepper.
Close the lid and seal the vent. Select the soup function.
Once cooking is complete, allow the pressure to release naturally for 10 minutes.
Carefully release any remaining pressure and serve hot.