Bring a large pot of salted water to a boil. Add the orzo and cook until al dente, about 8 minutes. Drain the pasta and toss it immediately with 1 Tbs. of the olive oil. Let the pasta cool completely in the refrigerator.
Put the sherry vinegar in a small bowl and gradually whisk in the remaining 1/2 cup of olive oil. Taste and season with salt, pepper, and additional sherry vinegar or olive oil as needed.
Put the cooked, cooled orzo in a large serving bowl. Add the cherry tomatoes, Gorgonzola, pine nuts, chives, and the vinaigrette and toss. Taste and season as needed with more salt and pepper. Serve within an hour or two of making.
Photo: Scott Phillips