Halve the vanilla pods lengthways and scrape out the seeds. Place the pod, seeds, sugar and vegetable stock in a pan, bring to the boil, then remove from the heat and allow to stand, covered, for 10 minutes.
Meanwhile, wash the asparagus, peel the bottom third and remove the woody ends.
Cut off the asparagus tips and set aside. Diagonally slice the spears very finely.
Juice the orange halves. Mix 2 tbsp orange juice with the vinegar, salt, pepper and oil.
Remove the vanilla pod from the stock. Add the vanilla stock to the orange juice mixture and beat well with a whisk.
Mix in the asparagus slices and leave, covered, for at least 1 hour in the fridge. Meanwhile, wash the rocket and shake dry.
Carefully wash and drain the strawberries. Halve or quarter depending on size.
Take the asparagus salad out of the fridge about 10 minutes before serving. Fold in the rocket and strawberries and garnish with the asparagus tips.