Smoky sweet potato gratin

1) Preheat the oven to 170C/Gas 3. In a small saucepan over a medium-high heat, melt the butter and add the garlic. When the garlic has browned, add the onions. Cook the onions until slightly caramelized, about 3 to 5 minutes.

2) Stir in the flour and the chipotle chillies and cook for an additional minute. Pour the cream and stock into the pan and stir. Season with salt and pepper, to taste. Bring the mixture to a simmer, stirring occasionally.

3) Layer about 1/3 of the sweet potato slices in a well greased 28cm baking dish. Drizzle 1/3 of the cream sauce over the potatoes and sprinkle some cheese on top. Repeat the steps, reserving about 25g of the cheese.

4) In a small bowl, mix together the breadcrumbs, reserved cheese and 1/2 the parsley. Set aside.

5) Cover the sweet potatotes with foil and bake in the oven for 30 minutes. Remove from the oven, discard the foil and top with the breadcrumb mixture. Return to the oven for an additional 15 minutes.

6) Remove from the oven and allow to sit for 5 minutes before serving. Garnish with the remaining chopped parsley and serve.