Pork and stone fruit salad with harissa-roasted sweet potato

• Scrub or peel the sweet potato. Cut the potato in half lengthwise, then crosswise into ¼-inch-thick half-moons.
• Peel the onion and cut it crosswise into ¼-inch-thick slices. Separate the slices into rings.

In a large frying pan over medium heat, warm 1 to 2 tablespoons oil until hot but not smoking. Add the sweet potato and onion and season generously with salt and pepper and as much harissa powder as you like. Cook, stirring occasionally, until the potato is tender and lightly browned and the onion starts to caramelize, 15 to 18 minutes. Remove from the heat and season to taste with salt and pepper. Meanwhile, prepare the pork.

• Pat the pork dry with a paper towel; season with salt and pepper.

In another large frying pan over medium-high heat, warm 1 to 2 tablespoons oil until hot but not smoking. Add the pork and cook, turning frequently, until browned but still faintly pink within, 8 to 10 minutes. Transfer to a cutting board to rest for 5 minutes, then cut into ½-inch-thick slices. 

While the pork is cooking, prepare the remaining ingredients and assemble the salad.

• Cut the plums in half and remove the pits; cut the fruit into ¼-inch-thick wedges.
• Trim the root end from the frisée; coarsely chop the leaves.

In a large bowl, toss together the plums and frisée with half the sherry vinaigrette (set aside any remaining vinaigrette for serving). Season to taste with salt and pepper.

Transfer the salad to individual bowls and top with the pork, sweet potato, and onion. Serve any remaining vinaigrette on the side.