Set the Instant Pot in saute mode and add the oil. When the oil is hot, add the onion and garlic and saute until the onion softens a bit.
Now turn off the Instant Pot. Add the carrots, celery, mushrooms, soaked and drained wild rice.
Then add the spices, including salt, ground pepper, onion powder, Italian seasoning, and curry powder.
Now add the water and mix well. Close the Instant Pot. Ensure the sealing ring is in place and set the vent to the sealing position. Cook the soup in "soup" mode or at high pressure for 30 minutes, and after the cooking is done, naturally release the pressure.
Then carefully open the Instant Pot. Set it in saute mode.
Mix the corn starch and water without any lumps. Add this slurry and the milk to the soup.
Mix and let it simmer for 5 minutes or until the soup thickens.
That's it; the soup is ready. Serve warm.
Adjust the salt and spices to taste.
You can vegetable broth instead of water.
Please check the FAQ section for other options and variations.