In a steamer set over boiling water steam the potatoes, cut into 3/4-inch pieces, covered, for 8 to 10 minutes, or until they are tender. While the potatoes are cooking, in a small bowl whisk together the vermouth, the shallots, the vinegar, and the lemon juice. Transfer the potatoes to a bowl, toss them with the vermouth mixture, and let them cool to room temperature. Add the oil, the smoked trout, the herbs, and salt and pepper to taste and toss the salad gently. Serves 6. SALAD56