Heat the olive oil in a large skillet over medium-high heat.
Season the diced chicken breast with sea salt, black pepper, and dried oregano, then sear in the skillet until golden brown on all sides.
Add the diced yellow onion and minced garlic to the skillet, sautéing for 2-3 minutes until the onion is translucent and fragrant.
Stir in the dry orzo and toast it for 1 minute, then pour in the chicken broth and bring the mixture to a gentle simmer.
Reduce heat to medium-low, cover the skillet, and cook for 8 minutes.
Place the broccoli florets on top of the orzo, cover again, and steam for 4-5 minutes until the orzo is tender and the liquid is mostly absorbed.
Remove the skillet from the heat and stir in the Greek yogurt, parmesan cheese, and lemon juice until the sauce is creamy and well combined.