For the dressing, finely grate the orange zest into a bowl and squeeze in all the juice. Halve the passion fruit and scrape in the pulp, then add the oil and mix together.Finely slice the cabbage, discarding the core. Remove the woody ends from the asparagus, then finely slice along with the trimmed spring onions and celery. Peel and coarsely grate the apple and carrot.Pop all the shredded fruit and veg into a large bowl. Pour over the dressing, mix well and season to taste.Enjoy straight away, or better still, cover and refrigerate for 1 to 2 days so the veggies soften slightly and the flavours mingle and develop. Mix well before serving and spoon over a little extra passion-fruit pulp, top with shredded spring onions and sprinkle with poppy seeds.