Heat oven to 200ºC/400ºF. Place shallot slices on large cookie sheet lined with parchment paper. Drizzle with 3 tablespoons olive oil. Place in oven for 7 minutes. Remove and flip. Place back in oven for 5-7 minutes.
Remove and add celery and apples, mixing to coat all with oil. Place back in oven for 5 minutes.
Sprinkle kale over other fruit/vegetables, place back in oven for 3-8 minutes or until kale has softened, but not turned crispy.
Mix together currants, vinegar, syrup, mustard, 2 tablespoons of oil and salt.
Remove fruit/vegetables from sheet to serving dish. Drizzle with vinaigrette. Sprinkle with walnuts. Serve.