Bring a medium pot of water to a boil. Rinse the farro, then add it to the boiling water. Reduce the heat and simmer for 45 to 90 minutes, or until fork tender. Drain and set aside.

In a small bowl, make the dressing by whisking together the olive oil, apple cider vinegar, mustard, garlic, ginger, honey (or maple syrup if vegan), and a pinch of salt and pepper. (It'll taste very tangy but it'll mellow once it's tossed with the hearty kale and farro).

Chop the kale into small pieces and place in a large bowl. Drizzle with ⅓ of the dressing, a squeeze of lemon, and a pinch of salt. Massage the kale until the leaves are soft and wilted. Add the cooked farro, hazelnuts, pomegranate seeds, feta, if using, and ⅓ more of the dressing. Season to taste with salt and pepper. Toss to coat and serve on plates or on a platter. Drizzle remaining dressing on top.