Hit the sauté function on the Instant Pot. Add 2 tablespoons unsalted butter and let melt. Once melted, add in the minced onion and celery and sauté for 3-4 minutes, stirring often, until softened and the onion is translucent.
Add in the rinsed rice and minced garlic, and cook for 1 minute, stirring constantly.
Add ½ cup dry white wine (or water) to the inner pot and use a spatula or wooden spoon to scrape off any browned bits off the bottom of the inner pot. Let this mixture cook for 1 minute, then hit cancel to turn off the sauté function.
Add 4 cups low-sodium vegetable broth, 1 tablespoon fresh thyme leaves, 2 small bay leaves, 1 teaspoon kosher salt, ½ teaspoon black pepper, 1 teaspoon dried onion flakes, 1 teaspoon onion powder, ½ teaspoon garlic powder, ⅛ teaspoon crushed red pepper flakes, and sliced carrots to the inner pot and stir to combine.
Place the lid on the Instant Pot, ensure the vent knob is sealed or locked, and then use the pressure cook or manual function to set to cook on HIGH pressure for 35 minutes. After the cook time has elapsed, let the pressure release naturally for at least 15 minutes. After 15 minutes you can opt do a quick pressure release if desired, by using the handle of a long utensil to knock the venting knob from seal to vent. Stand back to prevent yourself from being burned by steam.
Turn the Instant Pot back to sauté, by hitting cancel then the sauté function. Whisk together the 1 cup half and half with 1 tablespoon cornstarch until the cornstarch dissolves. Whisk that mixture into the soup, and cook for 2-3 minutes until thickened. Remove the bay leaves and sprigs of thyme as you come across them.
Once thickened, hit cancel to turn off the Instant Pot. Give the soup a tastes and adjust seasonings if needed. Serve as desired.
Video
Notes
Corn-Free: Replace cornstarch with arrowroot powder or tapioca starch.Add Chicken: Add up to 2 cups of shredded or diced cooked chicken to the soup when you add in the half and half.Lower the Sodium: Use low-sodium or salt-free broth and reduce or omit the kosher salt.Wine: Use a dry white wine suitable for drinking, such as a Pinot Grigio or Sauvignon Blanc OR omit and replace with water. For a Thinner Soup: Increase broth to a full 5 cups. Storage: Store leftover soup in an airtight container in the refrigerator for up to 5 days (3 days if the soup was made with the addition of chicken). Reheat in heat-safe bowls in 30-second intervals, adding a splash of broth or water to thin. I don't recommend freezing the soup due to the addition of cream.