01 - Heat olive oil over medium heat in a large pot. Add diced onion, carrots, and celery. Cook for 5 to 7 minutes, stirring occasionally, until vegetables are softened.
02 - Add minced garlic, dried thyme, smoked paprika, and tomato paste to the pot. Stir continuously and cook for 2 minutes until fragrant.
03 - Stir in the rinsed lentils and bay leaf. 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 flour, baking powder, salt, and dried herbs in a mixing bowl. Add the cubed cold butter and rub it in with your fingertips 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 tablespoonfuls of dumpling dough evenly over the surface of the simmering stew.
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 dumplings are puffed and cooked through. Ladle into bowls and serve hot, garnished with fresh parsley and a squeeze of lemon if desired.