Preheat your oven to 375°F and lightly grease a small baking dish with the olive oil.
Cut the chicken breast into bite-sized cubes and finely dice the bell pepper, onion, and broccoli.
In a medium mixing bowl, whisk together the Greek yogurt, chicken broth, minced garlic, sea salt, black pepper, and dried oregano until smooth.
Add the chicken cubes and chopped vegetables to the bowl, tossing thoroughly until every piece is coated in the yogurt mixture.
Transfer the mixture into the prepared baking dish, spreading it into an even layer.
Top the casserole with the parmesan cheese and sliced almonds for a golden, crunchy finish.
Bake for 25 to 30 minutes until the chicken is fully cooked through and the vegetables are tender.