Preheat oven to 180°C. Line a baking tray with baking paper. Place the walnuts in a medium bowl and drizzle with maple syrup. Season. Toss to coat. Spread evenly over the lined tray. Bake, turning occasionally, for 4-6 mins or until walnuts are caramelised. Set aside to cool.
Whisk the buttermilk, mayonnaise, vinegar and mustard in a small bowl until well combined. Season.
Ice sliced cabbage, fennel, in water and ice cubes for one hour. After slicing apple squeeze over lime juice to stop browning
Arrange the walnuts, combined cabbage, fennel, apple, pear, mint and dill on a large serving platter. Drizzle with the buttermilk mixture. Sprinkle with sesame seeds and serve immediately.