Spicy Lamb Meatball Flatbread

Sweet potato puree

1½ pounds sweet potatoes (1 large or 2 small)
½ cup Greek-style yogurt
1 teaspoon kosher salt
½ teaspoon pure vanilla extract

Meatballs

1¼ pounds ground lamb
2 garlic cloves, minced
1 teaspoon kosher salt
1 teaspoon smoked paprika
1 teaspoon ground cumin
½ teaspoon cinnamon
¼ teaspoon ground black pepper
2 tablespoons extra-virgin olive oil

Flatbread

4 pizza crust-flavored flatbreads
4 handfuls baby arugula

Optional toppings: thinly sliced red onion and cucumber, parsley, mint or cilantro, crumbled feta, sesame seeds, chile oil

Sweet potato puree: Preheat oven to 400°. Line a baking dish with aluminum foil. Prick each sweet potato a few times with a fork, and bake until very tender, about 1 hour. When cool enough to handle, peel the sweet potatoes, break them into large chunks and, in a food processor, puree with the yogurt, salt and vanilla until smooth. The sweet potato puree will keep for a few days in the refrigerator; re-warm before serving.

Meatballs: In a large mixing bowl, combine the lamb, garlic, salt, paprika, cumin, cinnamon and pepper, and mix to thoroughly combine. Roll mixture into 2-tablespoon-size balls, yielding about 24 meatballs.
In a large frying pan, heat the oil over medium heat. When the oil is shimmering hot, add the meatballs in a single layer with room between them. Let them cook without disturbing until a crust forms on the bottom side, about 2 minutes, then continue cooking, stirring often, until nicely browned on all sides and cooked through, about 10-12 minutes.

Assembly: Preheat oven to 375°, and toast the flatbreads until lightly browned around the edges and crisp, about 3-5 minutes. Top each flatbread with a smear of the sweet potato puree, about 6 meatballs, a handful of arugula leaves and the optional toppings of your choice. Serve hot or at room temperature.