In a small bowl combine the shallot, pomegranate molasses, vinegar, salt and pepper and whisk until the salt is dissolved.
Whisk in the olive oil and let vinaigrette stand at room temperature until salad is assembled.
Combine the arugula, romaine, pears and half of the pomegranate seeds in a large bowl.
Crumble half of the goat cheese over the ingredients in the bowl (this works best if the cheese is very cold).
Whisk the vinaigrette until uniform and add all but 2 tablespoons of it to the bowl.
Gently toss the salad with your hands or salad tongs, coating the ingredients well with the vinaigrette. If the salad seems dry, add the vinaigrette in small increments until it is dressed to your liking.
Crumble the remaining cheese over the salad and sprinkle the remaining pomegranate seeds and the pistachios over the top. Serve immediately.