Melt butter over medium heat in a large pot and sauté onions, carrots, and celery until onion is translucent.
Add water, broth, lentils, cumin, and paprika. Bring to a boil, reduce heat, and simmer until carrots and lentils are cooked through, about 30 minutes.
Pulse with an immersion blender or in a food processor until only small pieces remain, not completely smooth.
Add honey, lemon juice, allspice, and salt and mix well.
Serve with a dollop of plain yogurt.