Add the chickpeas to a large mixing bowl. Use a fork to mash the chickpeas - this doesn't need to be perfect, but you want at least 3/4 of the chickpeas to be mashed.
Add the avocado, mayo & chimichurri to the bowl and mix, mashing the avocado. Add the celery, sun-dried tomatoes, red onion & spinach and mix to combine. Taste and add salt, pepper and mustard. Cover and place in the fridge for 30-60 minutes.
To assemble, add about 1/3 cup of chickpeas to a wrap. Tuck in the sides and roll up like a burrito. Cut in half and repeat with the remaining ingredients.
Place on a platter and serve.
Video
Notes
There is already vinegar in the chimichurri, so the mustard is optional if you want some extra tang. I used about 1/2 tablespoon of mustard.
I used 6" flour tortillas to make the wraps. You could also use lavash, or large flour tortillas and cut these into pinwheels.
These are best served the same day. If you can wait to assemble until right before serving, this is best.