While the glut of high summer may be past, this time of year still sees an abundance of fantastic British produce in our shops, markets and gardens.
- Heat the oven to 190C/375F/gas mark 5 and lightly oil a large gratin dish.
- Peel the sweet potatoes and cut them into slices about as thick as a 10p piece. In a large bowl, toss the sweet potato slices with a tablespoon of oil, the chilli, garlic, cream and some salt and pepper. Arrange half the sweet potato slices in the gratin dish, spreading them out with your fingertips – you do not have to layer them piece by piece, but try to ensure they are mostly lying flat.
- Beat the peanut butter with the remaining tablespoon of oil, the lime zest and juice. Spread this mixture in dollops over the sweet potato in the dish. Add the remaining sweet potato and spread out. Pour over any cream remaining in the bowl.
- Cover the dish with foil and bake for about 20 minutes, then remove the foil. Bake for a further 30 minutes or so, until the sweet potato is completely tender and the top is browned and crisp. For extra crispness, finish under the grill for a couple of minutes, but watch carefully. Serve piping hot with a crisp, bitter salad to balance the gratin’s sweet richness.