In the seventeenth century, tomatoes ware the first vegetables to share a plate with pasta. With the advent of pasta primavera, all vegetables seem to have gotten into the act together. It's no wonder. The combination is naturally complementary. Noodles with their uniformity and consistent taste make an agreeable background to the colorful flamboyance of vegetables. The green of zucchini, broccoli, and asparagus, the red of bell peppers and tomatoes, the darker shades of eggplant and olives are all beautifully set off by the limpid paleness Of pasta dough. And so are the flavors—sweet versus tart, earthy versus pungent. The recipes that follow demonstrate that delicious variety and contrast.