
In a Dutch oven over medium heat, melt butter.
Saute celery, carrots, and onion until tender.
Gradually add milk. Cook and stir until thick and bubbly.
Add bouillon cubes, parsley, salt, seasoned salt, and cayenne pepper.
Simmer for 20 minutes, stirring often.
Meanwhile, cube half the potatoes and mash the other half. (Or use leftover mashed potatoes, if you have them!)
Add cubed and mashed potatoes to the soup.
Simmer for 20 to 25 minutes, stirring regularly, until hot and thick.
(If it gets too thick, add more milk.)
Serve with your favorite toppings.