Arrange a rack in the middle of the oven and heat the oven to 300ºF. Place 3/4 cup walnuts on a baking sheet. Bake until fragrant and golden brown, about 20 minutes. Set aside to cool.
Meanwhile, finely grate 1 small garlic clove into a large bowl. Add 2 tablespoons red wine vinegar, 1 teaspoon honey, 1/4 teaspoon dried oregano, 1/2 teaspoon kosher salt, and several grinds of freshly ground black pepper. Whisk to combine. While whisking constantly, slowly pour in 1/4 cup extra-virgin olive oil and whisk until combined.
Strip the leaves from 1 pound flat-leaf kale; discard the stems. Stack about 1/2 of the leaves and roll them up into a tight coil; cut crosswise into 1/4-inch-wide ribbons. Add to the dressing and repeat cutting the remaining leaves. Add to the dressing and toss thoroughly with your hands to coat, massaging the dressing into the kale for about 30 seconds; let sit to absorb the dressing while you prepare the remaining ingredients.
Prepare the following, adding each to the salad as you complete it: Thinly slice 1 small bunch scallions (about 1/2 cup). Pick the leaves from 1 small bunch fresh parsley and finely chop (about 1/4 cup). Finely chop 1 cup fresh dill fronds and tender stems. Pick the leaves from 6 large fresh mint sprigs until you have 1/2 cup, then finely chop. Coarsely chop the walnuts. Cut 6 to 8 ounces feta cheese into 1/4-inch thick slabs.
Toss with your hands to combine, letting the feta pieces crumble as you toss. Taste and season with more kosher salt or black pepper as needed. Let sit for at least 10 minutes to 1 hour before serving, as this salad will get more flavorful as it sits.