Beets-Lentils with Roasted Beets and Preserved Lemon

5 beets about 1 pound 1 teaspoon olive oil Salt and Pepper 1 cup French green lentils 1 carrot finely dices ½ small onion finely diced Aromaticts-1 bay leaf, 4 parsley branches, 2 thyme sprigs 1 Preserved Lemon or 2 teaspoons lemon zest 1/3 cup chopped parsley 2 tablespoons chopped mint, plus mint sprig for garnish Preheat the oven o 350 degrees. Peel 4 of the beets and cut them into small cubes. Set the last beet aside for garnish. Toss the cubed beets with the oil, season with salt and pepper and bake on a sheet pan until tender about 35 minutes, stirring once or twice. Meanwhile put the lentils in a pan with water to cover, add the carrot, onion, aromatics and ½ teaspoon salt and bring to a boil. Lower the heat and simmer until tender, but still a little firm, about 25 minutes. Drain well. Cut the preserved lemon into quarters and scrape off the soft pulp. Chop the pulp finely and stir 2 teaspoon into the dressing, finely chop the remaining skin. Toss the lentils with the toasted beets and the vinaigrette, the preserved lemon or lemon zest, parsley, and mint. Peel the remaining beet and finely grate it. Put the lentils on a platter and garnish with the grated beet and springs of mint.