Melt butter in skillet on medium heat.
Add onion and celery and cook until onions are clear but still crisp.
Add in rice, stir until coated and cook 1 minute.
Add in chicken broth, mushroom and parsley. Mix.
Bring to a boil. Once boiling, turn burner down to simmer and cover rice.
Simmer until rice is cooked, about 20 minutes.
Once done, stir and enjoy!