In a small bowl, whisk together the olive oil, balsamic vinegar, honey, Dijon mustard, salt, and pepper to create the dressing.
Place the sliced kale in a large mixing bowl and drizzle with half of the dressing.
Massage the kale with your hands for 2 to 3 minutes until the leaves become soft and dark green.
Add the sliced strawberries, red onion, toasted walnuts, and crumbled feta cheese to the bowl.
Drizzle the remaining dressing over the salad and toss gently to combine.
Serve immediately at room temperature.