Wash and dice the cucumber, red bell pepper, red onion (if using), and celery. Halve the cherry tomatoes and mince the fresh parsley. Set all prepped vegetables aside.

Bring a large pot of salted water to a rolling boil. Add the rotini pasta and cook until al dente, about 8-10 minutes. Drain and spread on a baking sheet to cool.

In a blender, combine avocados, water, garlic, horseradish, dill, salt, black pepper, and lemon juice. Blend until smooth, adjusting water for consistency.

In a large mixing bowl, add cooled pasta and pour the avocado dressing over it. Toss to coat, then fold in vegetables and chickpeas.

Serve in bowls, garnishing with nutritional yeast and parsley. Enjoy immediately or refrigerate for up to 2 hours to meld flavors.