In a 3- to 4-quart pot, combine the lentils with 5-1/2 cups of water. Add the cumin, 1 teaspoon salt and bring to a boil. Cover, and simmer gently for 25 minutes. Remove cover and let the lentils cool a bit. Slice the scallions in very fine rounds halfway up their green sections. When lukewarm, add the remaining salt, the lemon juice, the black pepper, oil, parsley, and scallions.
Stir and cool. Serve at room temperature or cold.