Quantity of Orzo when using other ingredients I am making an orzo salad, and I am adding Rotisserie chicken, green onions, cherub tomatoes artichoke hearts, lemon juice and zest as well as herbs. I am making this for a BBQ party with apprx. 25 guests and am not sure how much orzo to cook. Can anyone give me an idea. I want the ingredients to be evenly matched, not heavy on one over another. Thank you for any answers.
In my experience orzo behave much like rice, in the sense that grow a lot in volume after cooking.

I'm supposing that the orzo salad will be an apetizer or at least not a main dish, and you are talking about pearl barley which requires only 20-25 minutes of cooking with no pre-soak(but remember to wash it before cooking), so you can count about 50g per person.

50g x 25 = 1.250Kg (which can be rounded up to 1.5Kg just to be safe in case someone want a second dish)

If I recall correctly for every cup of orzo you add at least a cup and a half of water, so you'll need at least ~3.50L of water for the cooking