Place chicken in a slow cooker. In a medium bowl, add the spices, broth and lemon juice and mix. Pour on top of chicken and cook 5-7 hours on low or 3-5 on high (cooking times vary based on slow cooker).
When you're ready to start the sides, heat oven to 200F and wrap the pitas in foil and put in the oven.
Cut tomatoes and onion and place in a medium bowl. Top with feta cheese. Make vinegar mix by whisking olive oil, vinegar, oregano and salt and pepper to taste. Add as much as needed to tomato mixture reserving at least 1 tsp.
In a separate bowl, add and stir yogurt, chopped cucumber and 1 tsp vinegar mix.
Place chicken in a serving bowl and cut into chunks, topping with the leftover juices. Take pitas out of the oven and place on a plate. Place all food items on the table for serving. Put out extra tomatoes and lettuce for anyone (kids!) that may like their veggies plain.
Recipe by Maryann Jacobsen at http://www.maryannjacobsen.com/2014/05/slow-cooker-greek-chicken-pitas/