In a 2-qt. pot, heat butter over medium heat until the butter melts. Add in diced onions and cook until translucent.

Add dry rice, and stir to coat with butter-onion mixture. Cook for about 1 minute until some of grains start to brown just slightly. 

Pour in chicken stock. Let the stock 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 10 minutes. Turn off burner.

Add salt, pepper, dried oregano and lemon zest and replace lid, let steam for 2-3 minutes.

Remove lid and fluff with a fork.