How to Make It
Preheat the broiler. In a large saucepan, heat 2 tablespoons of the oil. Add the onion, celery, garlic and bay leaf and cook over moderate heat until softened. Add the lentils, tomatoes and stock; bring to a simmer over moderately high heat. Cover, reduce the heat and simmer, stirring occasionally, until the lentils are tender but still hold their shape, 45 minutes.
Meanwhile, set the eggplants on a foil-lined baking sheet and rub with the remaining 2 tablespoons of olive oil. Broil 6 inches from the heat, turning occasionally, until completely blackened and tender, about 20 minutes. Let cool.
Cut the eggplants in half lengthwise and scoop the flesh into a colander set over a bowl; discard the skins. Let the eggplant drain for 5 minutes, then transfer to a bowl and mash until smooth.
Stir the harissa and half the eggplant into the lentils until warmed through. Stir in the 1/3 cup of chopped parsley and season with salt and pepper. Ladle the stew into bowls; top with the remaining eggplant. Garnish with yogurt, chopped walnuts and parsley, mint leaves and a drizzle of pomegranate molasses and olive oil.