Preheat the oven to 325°F (150°C). Arrange the pistachios on a parchment-lined baking sheet. Roast in the preheated oven for 6-8 minutes until they start to smell toasty and have slightly darkened in color.

Remove from the oven and drizzle on ½ tsp of olive oil along with the flaky finishing salt, toss everything together so the salt begins to stick to the pistachios. Chop roughly, then set aside.

Place a rack in the bottom third of the oven; increase the oven temperature to 400°F (200°C).

Arrange the prepped sweet potatoes on one half of a heavy ovenproof skillet. Pour water in the skillet just to cover the bottom of the skillet. Cover the skillet tightly with aluminum foil and bake until the sweet potatoes are just tender, about 30-35 minutes. Transfer the sweet potatoes to a cutting board to cool. Slice the partially roasted sweet potatoes in half lengthwise.

Meanwhile, drain any remaining cooking water that is still in the skillet then return the skillet to the oven, empty, for 20 minutes.

After 20 minutes, remove the hot skillet from the oven and melt the butter in the skillet. Place the halved sweet potatoes cut side down into the melted butter and roast until the edges are browned and crisp, about 18-25 minutes. Set aside to cool slightly.

Combine the tahini, 2 TBSP lemon juice, 3 TBSP olive oil, garlic, honey, and salt in a small bowl, whisk to combine. Set aside.

Slice the prepared kale into thin strips and place in a large bowl. Pour the prepared dressing over the kale then with gloved or clean hands, massage the kale until it reduces in size by half and is tender.

Using a small spoon, scoop a little larger than bite-sized pieces of the caramelized, roasted sweet potato onto the prepared kale.

Top with the roughly chopped prepared pistachios, zest of 2 lemons, crumbled feta cheese, and red pepper flakes.