In a small bowl, whisk together the Greek yogurt, yellow mustard, pickle juice, smoked paprika, and garlic powder to create the special sauce.
Heat the avocado oil in a large cast-iron skillet over medium-high heat until shimmering.
Add the ground beef to the skillet, seasoning with sea salt and black pepper.
Use a spatula to break the beef into small pieces, then let it sit undisturbed for 3 minutes to develop a deep, crispy brown crust.
Stir the beef and cook for another 2 minutes until fully browned and crispy throughout.
Place the shredded romaine lettuce into a large serving bowl and top with the hot crispy beef, diced red onion, and sliced dill pickles.
Drizzle the prepared special sauce over the bowl and garnish with sesame seeds before serving.