Mix the dressing of the mustard, lemon juice and nutritional yeast together in a medium bowl and sit to the side.

Dice the onion, celery and parsley, and add to the dressing bowl. Mix everything together very well. Season with black pepper and a little bit of sea salt (optional) to suit your taste.

Cut an avocado lengthwise and remove pit. Scoop out the flesh and cut in lengthwise strips.

Lay a nori wrapper or the tortilla flat on a plate, and lay some avocado strips right down the center (the long way), avoiding a few inches from the top and bottom. Next spoon some of the mixture from the bowl on top of the avocado strips. Top with any add-ons you like. Wrap up as you would a burrito, by folding the bottom end up then wrapping the sides towards the middle. Hold in your hands so all the folds are held securely in place. Beginners- or anyone really!- should definitely eat over a plate! Enjoy and experiment to find your own favorite combinations. :) And share with us what you invented!