Once boiling, add saffron pistils (reduce heat, and let them bloom for about 5 minutes).
Put the heat at an higher temperature, add orzo. Remontez le feu sur plus fort, et ajoutez l'orzo. Keep an eye on it, taste regularly to know when it's cooked.
When the pasta is al dente, strain. Add a little butter (optional).
While the pasta is cooking, peel and mince the onion.
Brown it in a little olive oil, until translucent.
Add the shrimps to the onion, mix well. Just before they are done, add the lemon juice and the splash of soy sauce.
In a serving bowl, mix the pasta with the shrimp mixture. Sprinkle with parmesan (powder or petals) and a little bit of parsley.