Chop the onion and celery. Set a large 6-8 quart soup pot over medium heat. Add the butter, chopped onions, and celery to the pot. Stir and sauté for 3-5 minutes to soften the veggies.
Add the frozen potatoes O'Brien mix, and mixed vegetables to the pot. Pour in the vegetable broth. Then season with garlic powder, dried thyme, and crushed red pepper. Add 1 teaspoon of salt and ½ teaspoon of cracked black pepper to the pot. Stir and bring to a boil.
Once boiling, stir the vegetable soup, then continue to simmer for 10 minutes, or until the largest pieces of carrot and potato are soft and tender.
Add the cubes of cream cheese, stir and simmer until the cream cheese is completely melted into the broth creating a creamy soup base. The creamy base will be somewhat thin at this point. If you would like it to be thicker, ladle a small portion of broth out into a small bowl. Add 1-2 tablespoons of cornstarch to the broth. Stir well until the cornstarch is fully dissolved then pour the cornstarch slurry back into the simmering soup. Stir well as the soup thickens.
Taste, then salt and pepper as needed. Serve warm.
