Heat olive oil in a large deep skillet or Dutch oven over medium-high heat.
Season chicken cubes with salt and pepper, then brown in the skillet for 5 minutes until golden.
Add minced garlic and dried oregano, sautéing for 1 minute until fragrant.
Add the rice to the skillet and stir for 2 minutes to toast the grains.
Pour in the chicken broth and lemon juice, scraping the bottom of the pan to deglaze.
Bring to a boil, then reduce heat to low, cover, and simmer for 18 minutes.
Remove from heat and let stand covered for 5 minutes.
Fluff with a fork and stir in the lemon zest before serving.