In a large bowl, toss together the tomatoes, red onion, pickles, parsley, olive oil, vinegar and salt until coated. Set aside for at least half an hour but preferably 1 hour.
Dill Yogurt Sauce:
In a small bowl, whisk together the yogurt, lemon juice, olive oil, garlic powder, mint, salt, milk and dill until smooth. Taste and adjust if needed. Set sauce aside in the fridge.
Beef:
In another large bowl, add in the ground beef, onion, garlic, olive oil, parsley, salt, garlic powder, onion powder, paprika, pepper and mix together with your hands until combined. Divide the meat mixture into 4 equal portions. Using kitchen shears, cut open all of the pitas so that you have 2 round in tact round circles. Place the meat mixture on one of the pita circles and use a fork to flatten it out evenly. Cover with the other half of the pita. Drizzle your panini maker with olive oil and place the meat stuffed pita onto the hot panini press. Brush the top with olive oil and close the panini press for about 4 minutes. Repeat with the rest of the pitas and meat. Top with the salad and the yogurt sauce and enjoy!