Special equipment: 6 (1 1/2-cup) ovenproof soup plates and kitchen string
Directions
Heat 1/4 inch oil in a 10-inch heavy skillet over moderate heat until hot but not smoking, then cook bread, stirring frequently, until deep golden, about 1 minute. Transfer with a slotted spoon to paper towels to drain.
Tie thyme, parsley, chives, and bay leaves together with kitchen string to make a bouquet garni. Bring lentils, chestnuts, water, bouquet garni, and 1 1/2 teaspoons salt to a boil in a 3-quart heavy saucepan. Simmer, partially covered, until lentils are tender, 20 to 25 minutes. Discard bouquet garni and reserve 2 cups cooking liquid. Purée remaining soup in 2 or 3 batches in a blender (use caution when blending hot liquids), then pour through a large sieve into a large bowl, discarding solids. Whisk in enough of reserved cooking liquid to reach a thin, creamy consistency, then season with salt and pepper. (Soup will continue to thicken as it stands; keep reserved cooking liquid on hand to thin as needed.)
Preheat oven to 325°F.
Purée foie gras, whole eggs, yolks, and remaining teaspoon salt in a food processor until very smooth. With motor running, add 1 cup cream in a stream and blend until just combined (do not overprocess, or cream will curdle).
Put soup plates on 2 large baking sheets, then divide custard among them. Bake in upper and lower thirds of oven until just set, 15 to 20 minutes (some custards will cook quicker than others; check each one). Cool to warm.
Reheat soup, stirring occasionally, until very hot. Beat remaining ‚ cup cream until it just holds stiff peaks, then vigorously whisk whipped cream into soup. Pour soup over custards and sprinkle with croutons and almonds.
