To a large mixing bowl, add the turkey, egg, breadcrumbs, salt, pepper, cumin, paprika, garlic powder, cilantro, green onions, and jalapeno. Mix together until all the ingredients are well combined (I use my hands for this).
Place a large cast iron skillet over medium-high heat and swirl the pan with olive oil.
Shape the mixture into 5-6 patties. Dust both sides of each patty lightly with flour. Place patties into the hot cast iron pan. Turn down heat to medium and cook until browned, then flip, and cook again until browned on the other side and cooked completely through (burger should be firm in the center to the touch and bounce back a bit). Cooking time will depend on the thickness of your burgers. I cooked mine 5-6 minutes per side. Add the cheddar cheese on top of each burger in the last 1-2 minutes of cooking and cover the burgers to melt the cheese.
In the meantime, add your avocados to a bowl with the Greek yogurt, lime juice, and salt. Mash the avocados and stir until well combined. Set aside.
!To Assemble Burgers:
Place the burgers on the bottom bun. Spread a generous amount of the guacamole onto the top bun. Add lettuce, and tomato, and condiments of your choice. Serve.