Add the chopped celery, onion, vegan mayonnaise, chopped dill pickle and Dijon mustard into the bowl. Season with a pinch of salt and black pepper, then stir everything together with a spoon until well combined and creamy.
1 Stalk Celery, finely chopped, 3 Tbsp Finely Chopped Red Onion, 3 Tbsp Vegan Mayonnaise, 1 Tbsp Finely Chopped Dill Pickle, Pinch Salt and Black Pepper, 2 tsp Dijon Mustard