Wash hands with soap and water.
If not prewashed, gently rub broccoli and carrots under cold running water. Dry with a clean towel.
Scrub garlic, onion, lemon, celery, and red bell pepper with a clean vegetable brush under running water. Dry with a clean towel.
In a food processor or blender, add the chickpeas, garlic, and onion. Puree until smooth.
Add the yogurt, olive oil, lemon juice, salt, and pepper, and continue to puree until well combined.
Transfer hummus to a serving bowl and set aside.
Cut the celery sticks in half lengthwise, then cut them into 3-inch long strips. Remove the stem and seeds from the red bell pepper and cut into 2-inch long strips.
Arrange the broccoli, carrots, celery, and bell pepper on a serving tray. Serve with the yogurt hummus.