Bring chicken broth to a boil and add orzo. Cook about 10 minutes or until just past al dente, but before they get too soft. If you are using cauliflower, add it for the last 3-4 minutes of boiling. Drain pasta and cauliflower in a colander but do not rinse. Toss with half of the olive oil. (They will continue to cook while excess liquid drains out.) Let cool for about 15 minutes, occasionally stirring.
In a wok or sauté pan, heat the remainder of the olive oil and cook shallots until softened. Add scallions and cook for another minute. Add pistachios, cranberries, and zest and cook until all ingredients have warmed through.
Stir shallot mixture in with pasta and cauliflower. Add fresh parsley. Refrigerate at least two hours or overnight.