Boil the potatoes and carrots until fork tender.

While the potatoes and carrots are cooking, melt butter in medium saucepan over medium heat.

Once butter is melted, whisk together the butter, flour, 1 cup milk, Worcestershire sauce, onion flakes, celery salt, salt and pepper.

Once the flour mixture starts to thicken, stir in the remaining 4 Cups of milk.

Add the cubed Velveeta to the milk and allow to melt over medium heat, stirring occasionally.

Once the cheese is melted, stir in the potatoes and carrots and simmer for 10-15 minutes, stirring occasionally.