Preheat the oven to 200°C. Peel the sweet potato and cut it into even cubes. Rinse the courgette and slice. Finely mince the garlic and roughly chop the parsley.
Toss the sweet potato cubes with a tablespoon of olive oil, salt and pepper. Spread the cubes over a baking sheet and roast in the oven for approximately twenty minutes until tender. Meanwhile, heat half a tablespoon of olive oil in a frying pan and cook the courgette slices on both sides until golden brown. Remove the courgette from the pan and set aside.
Heat the remaining half tablespoon of olive oil in the same pan. Add the prawns along with the minced garlic and chili flakes. Cook the prawns quickly over high heat until they are completely pink and cooked through. Turn off the heat immediately and stir through the parsley.
Divide the roasted sweet potato and cooked courgette among plates. Spoon the warm prawns with the remaining garlic oil from the pan on top and serve immediately.