Roast the Sweet Potatoes:

1. Preheat the oven: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper.

2. Prepare the sweet potatoes: Toss the diced sweet potatoes in olive oil, salt, and pepper until evenly coated. Spread them in a single layer on the prepared baking sheet.

3. Roast: Roast the sweet potatoes for 20–25 minutes, flipping halfway through, until they are tender and lightly caramelized. Remove from the oven and let cool for a few minutes.

Prepare the Salad:

4. Massage the kale: While the sweet potatoes cool, place the chopped kale in a large bowl. Add a small drizzle of olive oil and a pinch of salt. Massage the kale for 2–3 minutes until it softens and becomes more tender.

5. Add the other ingredients: Add the roasted sweet potatoes, sliced red onion, and crumbled feta cheese (if using) to the bowl with the kale. Toss everything together gently.

Make the Dressing:

6. Whisk the dressing: In a small bowl, whisk together the Dijon mustard, honey, apple cider vinegar, Greek yogurt, olive oil, salt, and pepper until smooth and creamy.

Assemble and Serve:

7. Dress the salad: Drizzle the creamy honey mustard dressing over the salad and toss to coat all the ingredients evenly.

8. Garnish: Sprinkle the toasted pumpkin seeds or sunflower seeds on top for added crunch (optional).

9. Serve: Serve the salad immediately or refrigerate for up to 1 hour before serving.