1cup thinly sliced well-rinsed scallions (green onions), with green tops
1cup shelled walnut halves
Chopped fresh Italian (flat-leaf) parsley, for garnish
Rinse the lentils and sort through them carefully, discarding any pebbles you may find.
Transfer the lentils to a large pot and add the carrots, the onion stuck with the cloves, chicken stock, bay leaf, and thyme. Set over moderate heat and bring to a boil. Reduce to a simmer, skim any foam that may appear, cover, and cook until the lentils are tender but still hold their shape, about 25 minutes (lentil cooking time varies widely). Do not overcook.
While the lentils are cooking, combine the vinegar, garlic, and walnut oil in a blender or a food processor, and process until smooth and creamy.
When the lentils are done, drain them, discard the carrots, onion, cloves, and bay leaf, and pour the lentils into a mixing bowl. Rewhisk the dressing and pour it over the still-hot lentils. Toss gently, season generously with salt and pepper, and let the salad cool to room temperature. Toss again, cover, and refrigerate overnight.
Just before serving, add the scallions and walnuts. Add an additional tablespoon or two of vinegar or walnut oil if you like, and toss gently. Sprinkle heavily with the chopped parsley and serve, accompanied by a peppermill.