Preheat oven to 2000C/gas mark 6, and line a large baking sheet with foil.
Cut sweet potatoes in half - length ways, and bake for 30-45 minutes.
Toss the chickpeas with olive oil and spices, and place on a foil-lined baking sheet.
Once baked, rub the sweet potatoes with a bit of olive oil and place face down on the baking sheet with the chickpeas (or another baking sheet depending on size). Bake for roughly 25 minutes, until chickpeas are golden and potatoes tender.
Prepare the parsley-tomato topping by tossing tomato and parsley with lemon juice and setting aside to marinate.
Serve sweet potatoes flesh side up, top with chickpeas and drizzle with tomato dressing and optional hummus.