Melt the butter in a medium pot over medium heat. Add the vermicelli and stir constantly until deep golden brown, about 3 to 5 minutes. (If using onion and garlic, add them with the vermicelli and soften.)
Add the rinsed rice and stir for about 1 minute, until coated and glossy.
Pour in the chicken broth and salt. Bring to a boil.
Cover, reduce the heat to low, and cook undisturbed until all the liquid is absorbed, about 20 minutes.
Remove from the heat and let it sit, covered, for 10 minutes. Fluff with a fork and serve.