1. Heat oil in a large pot over medium heat. Add rice and cook, stirring often, until starting to turn golden in spots, about 8 minutes. Stir in onion and cook until translucent, about 4 minutes.
2. Meanwhile, combine garlic, cilantro, 2 cups broth, and the salt in a blender; whirl until smooth, about 2 minutes. Pour over rice and stir in remaining 2 cups broth.
3. Bring to a boil, reduce heat to low, cover, and cook until rice is tender to the bite and liquid has been absorbed, 15 to 20 minutes.