First make the curry dressing by mixing all of the dressing ingredients together in a small bowl. Cover and refrigerate until needed.
Now make the salad. Slice the red and green apples into thin slices. Place in a bowl with the lemon juice. Toss together to coat the apple slices (this will prevent the apple slices from turning brown).
Take the fennel and slice off the green fronds.Cut a slice off the base. Slice the fennel in half length-ways, then cut out the core at the base of the fennel (this part is a little tough). Cut each of the two fennel halves into thin slices.
Now it's time to assemble. Divide the salad leaves between 3 or 4 bowls. Top with the fennel slices, followed by the celery and sliced apple.
Toss everything together then arrange the radish slices and walnuts on top.
Gently fold the Prosciutto di San Daniele slices and arrange on top of each bowl, then sprinkle with shaved Grana Padano.
Drizzle on a little of the salad dressing and serve immediately.