Stir in lentils, salt, ginger, pepper, cumin, chili powder, and paprika, then pour in broth. Increase heat to high and bring to a boil. Reduce heat to medium-low, cover, and simmer until lentils and vegetables are soft, about 30 minutes.

Purée soup in the pot with an immersion blender until smooth. Increase heat to medium-high and cook until simmering, about 10 minutes. Add water as needed to thin to desired consistency.