Place the drained chickpeas in a large bowl and mash with the back of a fork until broken down. You can leave some chunks for added texture.
Finely chop the red onion, celery and roughly chop the capers. Add to the mashed chickpeas.
Add the vegan mayo, juice of half a lemon, mustard, garlic and parsley. Give it a good stir until fully combined.
Taste and season with salt and black pepper and serve however you like best!