1lb. thick-sliced bacon, diced
1white onion, diced (2 cups)
1cup minced celery
1Tbsp. minced garlic
2Tbsp. all-purpose flour
6cups peeled and diced russet potatoes (2 lb.)
1Tbsp. dry mustard
3cups low-sodium chicken broth
1Tbsp. Worcestershire sauce
1tsp. Tabasco sauce
4cups shredded sharp Cheddar
Salt, black pepper, and cayenne pepper to taste
Cook bacon in a large pot over medium-high heat until crisp. Remove bacon with a slotted spoon to a paper-towel-lined plate; set aside. Pour off all but 2 Tbsp. drippings.
Add onion, celery, and garlic to drippings in pot and sweat over medium heat until onion is softened, about 5 minutes.
Stir in flour and cook 1–2 minutes. Add potatoes, dry mustard, and paprika; cook, stirring to coat potatoes, 1 minute. Stir in broth, Worcestershire, and Tabasco. Bring to a boil, reduce heat to medium-low, and cook, partially covered, until potatoes are soft, 10–15 minutes. Coarsely mash potatoes, then stir in Cheddar and half-and-half until Cheddar is melted, 2 minutes. Remove soup from heat; season with salt, black pepper, and cayenne.
Garnish servings with bacon and scallions.