Heat olive oil in a large saucepan over medium high heat. Add in onion and saute 3 minutes, stirring occasionally.

Add in rice and toast 3 minutes, until rice is lightly toasted.

Pour in chicken broth and salt. Bring to a boil over high heat.

Reduce the heat to low and cover with lid. Simmer 15 minutes, until all liquid has been absorbed and rice is tender.

Stir in lime juice, cilantro, and butter until melted. Add more salt, to taste. Serve hot.