Wash and thoroughly dry the romaine lettuce, then chop it into bite-sized pieces. Prepare the tomatoes, red onion, pickles, avocado, and parsley and set aside.
Make the sauce by stirring Greek yogurt, Dijon mustard, ketchup, pickle juice, garlic powder, smoked paprika, and black pepper together in a small bowl until smooth. Taste and adjust the seasoning if needed.
Add the ground beef to a bowl and gently combine it with smoked paprika, garlic powder, onion powder, salt, black pepper, oregano, and chili flakes.
Heat a large skillet over medium-high heat. Add the olive oil if needed, then add the seasoned beef.
Let the beef cook briefly before breaking it into crumbles. Continue cooking, stirring occasionally, until the beef is browned and reaches an internal temperature of 160°F (71°C).
Divide the chopped romaine between four serving bowls.
Arrange the tomatoes, red onion, pickles, avocado, and parsley over the lettuce.
Divide the warm cooked beef between the four bowls.
Drizzle each bowl with the Greek yogurt burger sauce or serve the sauce on the side.
Finish with additional black pepper or parsley if desired and serve immediately.