3 tablespoons unsalted butter 1 1/2 cup chopped onions 1 carrot, chopped (optional) 1 cup red lentils, washed and drained 1 1/2 teaspoon paprika 2 tablespoons tomato paste (optional) 6 cups chicken stock or water 1 cup milk (optional); if no milk, add fresh lemon juice to taste salt and freshly ground black pepper ground red pepper to taste 2 slices bread, about 1/2 inch thick, crusts removed 3 tablespoons chopped fresh mint OR 1 tablespoon crumbled dried mint
In a medium saucepan, melt butter over moderate heat. Add onions, lentils, and carrots. Cook, stirring occasionally, about 5 minutes. Add paprika and tomato paste and stir well to mix. Reduce heat to low and cook for a few minutes. Gradually add stock or water, stirring constantly. Simmer, uncovered, until lentils are very soft, about 30 minutes.
Transfer to blender or food processor and puree until smooth. Return to saucepan and add milk or lemon juice, salt, pepper, and red pepper. Simmer over low heat until heated through.
Toast bread until crisp and golden on both sides, then cut into cubes. Or first cut bread into cubes and then saute in butter until golden. Ladle into individual bowls. Sprinkle with mint and croutons.