Start the stew: Set a large Dutch oven or soup pot over medium heat.

Add the olive oil to the pot and let it warm for about 30 seconds.

Add the onion, carrots, celery, and 1/2 teaspoon of the salt to the pot. Cook for 8 minutes, stirring now and then, until the vegetables soften and the onion looks translucent.

Add the garlic, tomato paste, and dried thyme to the pot. Stir for 1 minute, until the garlic smells fragrant and the tomato paste darkens a shade.

Add the lentils to the pot and stir once so they are coated with the vegetables.

Pour the vegetable broth into the pot and raise the heat to high. Bring the liquid to a boil.

Lower the heat to medium-low so the stew bubbles gently. Partly cover the pot and cook for 20 minutes, stirring once or twice so the lentils do not stick on the bottom.

Add the chickpeas to the pot. Continue to simmer for 10 to 15 minutes, until the lentils are tender and the broth has thickened slightly.

Mix the dumplings: While the stew simmers, put the flour, baking powder, the remaining 1/2 teaspoon salt, and the black pepper in a medium bowl. Stir with a fork to combine.

Add the melted butter, milk, and half of the chopped parsley to the bowl. Stir just until a thick, soft dough forms. Do not keep stirring once the flour disappears.

Taste the stew and add more salt and black pepper if needed. Adjust the heat so the stew is bubbling gently, not boiling hard.

Steam the dumplings: Spoon the dumpling dough in 8 mounds onto the surface of the stew, spacing them across the pot.