01 - Heat a dry skillet over medium heat. Add the walnut halves and toast, stirring frequently, until fragrant and golden, about 3 to 5 minutes. Remove from heat and let cool completely.
02 - Place the finely sliced kale in a large salad bowl. Drizzle with 1 teaspoon of olive oil and a pinch of salt. Massage the kale with your hands for 1 to 2 minutes until the leaves soften and darken in color.
03 - In a small bowl or jar, whisk together the fresh orange juice, lemon juice, Dijon mustard, honey or maple syrup, olive oil, sea salt, and black pepper until well combined and emulsified.
04 - Add the thinly sliced apples, toasted walnuts, crumbled feta cheese if using, dried cranberries, and sliced red onion to the bowl with the massaged kale.
05 - Pour the citrus dressing over the salad and toss thoroughly to combine, ensuring all ingredients are evenly coated with the dressing.
06 - Taste and adjust seasoning with additional salt or pepper if needed. Serve immediately or refrigerate for up to 1 hour before serving.