In a 2-qt. pot, heat butter and olive oil until the butter melts. Add in diced onions and cook until translucent.
Add dry rice, and stir to coat with butter mixture. Cook for about 1 minute.
Pour in chicken stock, dried oregano, and lemon zest. Let the pot come up to a boil, and then immediately cover and turn the stove to the lowest heat setting. Allow rice to cook and absorb all the liquid. About 15 minutes.
Once it is finished cooking, fluff with a fork.