In a large skillet, fry the bacon and place onto paper towels to drain. Reserve 2 tablespoons of the bacon grease and discard the rest.
4 slices bacon
In the reserved bacon grease, cook the onions and celery until tender. Add the minced garlic cook 1-2 minutes more.
2 tablespoons bacon fat, 1 cup onion, ½ cup celery, 1 teaspoons fresh garlic
To the crock pot, add the stock, vegetable mixture, salt, pepper, dry mustard, dried tarragon, and garlic powder. Whisk to combine.
6 cups reduced-sodium chicken broth, 1 teaspoons salt, ½ teaspoons white pepper, 2 teaspoons dry mustard, 2 teaspoons dried tarragon, ¼ teaspoons garlic powder
Add the potatoes and set the slow cooker for 6 hours on LOW until the potatoes are tender.
4 cups red potatoes
Just before serving, use an immersion blender to smooth out the potato soup to desired taste.
Stir in the heavy cream and shredded Gruyere cheese. If desired, add in the sour cream.
½ cup heavy cream, 6 oz Gruyere cheese, 2 tablespoons sour cream
Serve with crumbled bacon pieces and cheddar cheese for topping.