In a large pot add the olive oil, potatoes, carrots, celery and onion. Season with salt and pepper and cook over medium heat 3-5 minutes or until the onions are translucent.
Pour in the chicken stock, cover and cook with a low boil until the carrots and vegetables are tender then fold in Dilled Brussels Sprouts.
In a small bowl blend the flour, sour cream, juice from the jar and dill then temper the mixture by whisking in ¼ cup of the hot soup broth. Pour the tempered sour cream blend into the soup 2 tablespoons at a time whisking constantly until it’s all combined.
Simmer uncovered 3-5 minutes until it thickens. Fold in the butter, stirring until combined then taste and adjust salt and pepper as you like.
(Optional) garnish with thinly sliced brussels sprouts and serve hot.