Add the cilantro, spinach, and broth to a blender or food processor and pulse until the cilantro and spinach are finely pureed. Add the chicken broth, milk, and salt and blend once more to form a cohesive mixture.
In a large skillet, heat the olive oil and butter. Once the butter is melted and hot, add the rice and saute until lightly toasted, about 3-4 minutes.
Once the rice is toasted, add the onion and garlic and cook for 1 more minute.
Pour in the cilantro spinach mix and stir to combine.
Bring to a boil, cover, reduce heat to low, and cook for 20 minutes.
Uncover, fluff with a fork, and enjoy!