• Peel the sweet potato. Cut the potato in half lengthwise, then crosswise into ¼-inch-thick half-moons.

In a medium sauce pot, add the sweet potato and enough lightly salted water to cover by 1 inch. Bring to a boil, reduce to a simmer, and cook until tender, 8 to 10 minutes. Drain and return to the pot. Add the balsamic vinegar and 2 teaspoons [1 TBL] butter or oil. Using the back of a spoon or a masher, coarsely mash the potato. Season to taste with salt and pepper. Cover and keep warm.
While the sweet potato cooks, prepare the korma.

• Peel and thinly slice enough onion to measure 1 cup [2 cups].
• Cut a small corner from the ground lamb packaging and drain off any excess liquid. Transfer to a plate; pat dry with a paper towel.

In a large frying pan over medium-high heat, warm 1 tablespoon oil until hot but not smoking. Stir in the onion and cook until starting to soften, 1 to 2 minutes. Add the lamb and coriander spice blend, season with salt and pepper, and cook, stirring to break up the meat, until lightly browned but not yet cooked through, 2 to 3 minutes. Add the korma base and ¼ cup [½ cup] water and cook, stirring occasionally, until the lamb is cooked through, 3 to 4 minutes. Remove from the heat and season to taste with salt and pepper.
While the lamb korma cooks, prepare the cilantro and the naan.

• Coarsely chop the cilantro for garnish.

On the stovetop directly over a flame, or in a dry medium frying pan over medium heat, warm the naan, turning once, until lightly toasted, about 30 seconds per side. Alternatively, toast them in a toaster oven.

Transfer the sweet potato mash and lamb korma to individual bowls and garnish with the cilantro. Serve with the toasted naan.