1/3 cup flour
½ tsp. kosher salt
6 tbsp. unsalted butter, cubed and chilled
1 ½ tbsp. Hungarian paprika
1 large yellow onion, finely chopped
6 cups vegetable stock
1 small head cauliflower, large stem removed, cut into florets
1 medium carrot, peeled and finely chopped
4 celery sticks
Kosher salt and freshly ground black pepper, to taste
1 small bunch flat-leaf parsley, stemmed and finely chopped
Make the dumplings: In a bowl, stir together flour and salt; add 2 tbsp. butter, and using your fingers, rub into flour until pea-size crumbles form. Add egg, and stir until dough forms; refrigerate until ready to use.
Heat remaining butter in a 6-qt. saucepan over medium-high heat; add paprika and onion, and cook, stirring, until soft, about 5 minutes. Add vegetable stock, cauliflower, celery and carrot; season with salt and pepper, and bring to a boil. Reduce heat to medium, and cook, stirring occasionally, until vegetables are tender, about 15 minutes. Using a ½-tsp. measuring spoon, portion out and drop all dumpling dough into simmering soup; cook, stirring occasionally, until dumplings are cooked through, about 3 minutes. To serve, ladle soup and dumplings into 4 serving bowls, and garnish with parsley.