Set the pressure cooker to Sauté. Add the oil, then cook the onions, carrots, celery, and garlic until softened. Stir in the mushrooms and cook for 1–2 minutes, stirring often. Deglaze the pot with a splash of the wine, scraping up any browned bits.
Stir in the tomato paste until it coats the vegetables. Turn off the Sauté setting.
Stir in the diced tomatoes and bay leaves. Pour in the broth and remaining wine, then add the pearl barley and remaining soup ingredients. Stir well to combine.
Lock the lid and cook on High Pressure for 20 minutes. Allow a natural pressure release for 5–10 minutes, then carefully release any remaining pressure. Open, stir, and serve.
Notes
Stovetop instructions: Sauté the veggies in a large pot or Dutch oven over medium to high heat. Add the remaining ingredients to the soup pot, reduce the heat to low heat, cover the pot, and cook for at least 50 to 60 minutes.RECIPE TIPSDon't overfill the instant pot past the fill line! If you do it will not be able to pressure cook.To thicken your soup, let it sit for about half an hour. The starch from the barley should release into the soup.If you prefer a thinner soup, the barley can be cooked separately and added to the soup just before serving it. OMake preparing faster and use pre-cut vegetables from the grocery store.INGREDIENT NOTES/SUBSTITUTIONSVegetable broth can be substituted with chicken or beef broth.Wine can be left out.Mushrooms any type of mushroom will work in this recipe. Store leftover soup in the refrigerator for up to three days or freezer for up to three months.