Preheat the oven to 425° F. Line a baking sheet with parchment.Combine the lamb, shallots, parsley, oregano, paprika, dijon, salt, pepper, and chili flakes in a bowl. Coat your hands with a bit of olive oil, and roll the meat into 3 tablespoon size balls, placing them on the prepared baking sheet. Add the lemon wedges and garlic (for the dressing) to the baking sheet. Bake for 15-20 minutes, until the meatballs are crisp and cooked through on the inside.During the same time, toss together the sweet potatoes with 2 tablespoons olive oil and a pinch of salt and pepper on another baking sheet. Bake 25 minutes, until the potatoes are crispy.Meanwhile, make the dressing. Whisk together the olive oil, red wine vinegar, herbs, olives, and pepperoncini. Grab the meatballs from the oven, remove the lemons and garlic. Juice the lemons into the dressing. Chop the garlic and mix into the dressing. Add the feta.To assemble, add Tzakiki and lettuce to a bowl. Top with meatballs and spoon the dressing over the meatballs. Add the potatoes and any other desired toppings. Serve with additional Tzakiki (of course!).