Add in all the chopped veggies, chicken stock, garlic powder, and dried mustard powder. Bring to a boil. Cover and simmer 10 minutes or until all the veggies are tender. Turn heat to low.
In a small bowl, whisk together cold water and cornstarch until smooth. Slowly pour the cornstarch mixture into the pot of soup and continue to stir. In 1-2 minutes the soup will start to thicken at this point turn off the burner.
3 Tablespoons cornstarch, 1/2 cup cold water
Add in the shredded cheese, parsley, salt and black pepper. Once cheese is melted and incorporated, stir in the half & half. Add in more seasonings, if necessary.