►Arrange scallops on a large rimmed baking sheet lined with paper towels. Place more paper towels on top of scallops, then top with another large rimmed baking sheet for 5 to 10 minutes to absorb excess moisture.
►Remove top baking sheet and towels from scallops. Season with salt and pepper. Working in three batches, heat 1 tablespoon vegetable oil per batch in non-stick skillet over high heat until smoking. Place of scallops around the circumference of the pan, flat side down for 2 to 3 minutes per side. Remove from heat and transfer to plate or baking dish. Repeat these steps, allowing the pan and oil to reheat before starting each batch.
►After the final batch, wipe pan clean with paper towel. Set heat to medium- high and add olive oil. Once oil is shimmering, add orzo and stir until coated with oil, then add vegetable stock and salt. Bring to a boil. Reduce heat to medium, cover, and cook until orzo is al dente and almost all the liquid is dissolved, about 5 to 7 minutes.
►Transfer orzo to serving platter, arrange scallops on top, and finish with pine nuts, chives, and parmesan. Serve with a side of lemon slices if desired.