Haricots verts are thin, tender green beans. If you can't find them, use trimmed regular green beans, but add them to the pasta after 8 minutes of cooking since they'll take longer to cook. You can make the salad ahead, but dress it just before serving so the beans don't turn drab.
Cook the pasta according to package directions, omitting salt and fat. Add haricots verts during the final 2 minutes of cooking. Drain and rinse pasta mixture under cold water; drain well.
Place the pasta mixture, pistachios, 1 tablespoon thyme, and 1 tablespoon lemon rind in a large bowl; toss gently to combine.
Combine remaining 1 tablespoon thyme, remaining 1 tablespoon lemon rind, shallots, Champagne or white wine vinegar, and garlic in a small bowl, stirring well with a whisk. Gradually add olive oil, stirring constantly with a whisk. Add salt and black pepper; stir with a whisk. Drizzle over pasta mixture, and toss gently to coat. Top each serving with Parmesan cheese.