Melt butter in large stock pot. Add chicken stock and salt (if needed). Bring to a summer and add 1-2 cups of popcorn and cook for 30 seconds to 1 minute on med heat..
Pour the mixture in a medium strainer. Really mash it to get all the popcorn out. This will be your thickener.
Pour liquid back in cooking pot. and repeat with another 1-2 cups of popcorn. Strain and keep doing this process until all the popcorn is used up (except the popcorn you set aside for garnish). You can make this soup as thick or thin as you like it.
After all the popcorn has been done, top with butter (if desired) and serve.