01 - Heat olive oil over medium heat in a large pot. Add the diced onion, carrots, and celery. Sauté for 5 to 7 minutes until the vegetables are softened and the onion is translucent.
02 - Stir in the minced garlic, dried thyme, smoked paprika, and tomato paste. Cook for 2 minutes, stirring constantly, until fragrant.
03 - Add the rinsed lentils and bay leaf to the pot. Pour in the vegetable broth and bring to a boil. Once boiling, reduce heat to low, cover, and simmer for 25 to 30 minutes until lentils are tender. Season with salt and pepper to taste.
04 - While the lentils simmer, combine the flour, baking powder, salt, and dried herbs in a mixing bowl. Add the cubed cold butter and rub it in with your fingers until the mixture resembles coarse crumbs. Stir in the milk until a soft, slightly sticky dough forms.
05 - Remove and discard the bay leaf from the lentil mixture. Drop rounded spoonfuls of dumpling dough (about 1 tablespoon each) onto the surface of the simmering stew, spacing them evenly.
06 - Cover the pot tightly and cook over low heat for 15 minutes. Do not lift the lid during steaming, as the dumplings need consistent heat to cook properly.
07 - Check that the dumplings are puffed and cooked through. Ladle into bowls and serve hot, garnished with fresh parsley and a squeeze of lemon if desired.