In a large pan with a lid, preheat the pan over medium-high heat and add in the olive oil, onion, and ½ teaspoon of salt. Cook the onion until it just begins to soften, about 2-3 minutes. Add in the rice and orzo and cook while stirring constantly for 2 minutes. Add the garlic and cook until fragrant, about 60 seconds.
Pour in the broth, give everything a good stir, and bring to a boil. Once boiling, reduce the heat to low and cover the pan with the lid. Cook until the rice and orzo are tender, about 20-22 minutes. Remove the pan from the heat, and let the pilaf sit, covered, for 8 minutes. Fluff the pilaf with a fork, and stir in the parsley. Season with salt and pepper and serve.