Peel and cube the Sweet Potato (1.25 pound) into 1-inch cubes.
Add potatoes to a large pot, covering completely with water. Add Salt (1 teaspoon) to pot.
Bring to a boil and cook 8-12 minutes, or until fork tender. Drain well with a colander.
In a large bowl combine the Lemon Juice (4 teaspoon), Worcestershire Sauce (2 teaspoon), Apple Cider Vinegar (1 tablespoon) and Garlic (1 teaspoon). Toss with this the sweet potatoes and refrigerate until cold.
When ready to serve (even if it's the next day), mix with the potatoes the Mayonnaise (1/4 cup), Sour Cream (1 tablespoon) and Blue Cheese (2 tablespoon). Top with the Scallion (2).