Bring 4 quarts salted water to a boil in a large pot. Stir in all the fettuccine. Cook until tender but still firm, and drain immediately. Transfer the pasta to a large mixing bowl, add the olive oil and chopped onion, and toss gently to combine. Set aside to cool to room temperature.
Bring another 4 quarts salted water to a boil. Add the snow peas and sugar snap peas. Cook 1 minute,drain and plunge the peas immediately into a large bowl of ice water. Let stand for 10 minutes. Drain the peas and pat thoroughly dry.
Add the peas to the pasta in the mixing bowl along with the prosciutto,tomatoes, bell peppers,scallions and chives or herbs. Season with salt and pepper, sprinkle on the raspberry vinegar, and toss gently.
Toss the pasta and vegetables with the grated cheese, taste and correct the seasoning. Arrange the pasta on a large serving platter. Scatter the olives and citrus zest over the pasta and serve at room temperature.