Preparation Cook orzo in a large pot of boiling salted water until barely al dente, 5 to 6 minutes. Drain in a colander and rinse under cold water to stop cooking. Transfer orzo to a 2-quart heavy saucepan and add stock, zest, and thyme. Simmer over moderate heat, stirring constantly, until stock is absorbed, about 5 minutes. Stir in cheese, butter, salt, and pepper and serve immediately. Cooks' note:Orzo can be parboiled 2 days ahead, then tossed with 1 tablespoon olive oil and chilled, covered. Bring to room temperature (or run under hot water in a colander)before proceeding.
Preparation Cook orzo in a large pot of boiling salted water until barely al dente, 5 to 6 minutes. Drain in a colander and rinse under cold water to stop cooking. Transfer orzo to a 2-quart heavy saucepan and add stock, zest, and thyme. Simmer over moderate heat, stirring constantly, until stock is absorbed, about 5 minutes. Stir in cheese, butter, salt, and pepper and serve immediately. Cooks' note:Orzo can be parboiled 2 days ahead, then tossed with 1 tablespoon olive oil and chilled, covered. Bring to room temperature (or run under hot water in a colander)before proceeding.