1-Preheat your oven to 375°F (190°C): Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish and set it aside.
2-Heat the olive oil in a large: Heat the olive oil in a large skillet over medium heat. Add the onion and cook for 3-4 minutes until softened. Stir in the garlic and cook for 30 seconds. Add the lean ground beef and cook until browned, breaking it into small crumbles. Drain any excess fat if needed. Season with paprika, oregano, salt, and pepper.
3-In a medium bowl, whisk together the: In a medium bowl, whisk together the Greek yogurt, light sour cream, and cornstarch until completely smooth.
4-Arrange half of the sliced potatoes in: Arrange half of the sliced potatoes in an even layer in the prepared baking dish. Top with half of the cooked beef mixture. Spread half of the yogurt mixture evenly over the beef, then sprinkle with half of the shredded cheddar cheese.
5-Repeat with the remaining potatoes, beef, yogurt: Repeat with the remaining potatoes, beef, yogurt mixture, and the remaining cheddar cheese.
6-Slowly pour the beef broth around the: Slowly pour the beef broth around the edges and evenly over the casserole. The broth may seem like a lot at first, but the potatoes will absorb most of it as the casserole bakes. Avoid pouring it all into one spot to help the potatoes cook evenly.
7-Cover the baking dish tightly with aluminum: Cover the baking dish tightly with aluminum foil and bake for 45 minutes.
8-Remove the foil and continue baking for: Remove the foil and continue baking for 15-20 minutes, or until the potatoes are fork-tender and the cheese is melted and lightly golden.
9-Let the casserole rest for 10 minutes: Let the casserole rest for 10 minutes before serving. Garnish with freshly chopped parsley and enjoy.