Cook the farfalle in boiling salted water according to package directions until al dente. Remove from heat and drain.
Rinse and slice celery.
Rinse and quarter peppers, remove seeds and cut into thin strips.
Rinse and quarter tomatoes, remove seeds and dice.
Peel, halve and cut onion into strips. Rinse broccoli and drain well.
Boil the broth and add the celery. After 2 minutes, add broccoli, onion and pepper. Let simmer for about 5 minutes. Finally add tomatoes and farfalle and season with salt and pepper. Place in a bowl and serve with pesto, as desired.