AGA cooker

The Swedish physicist and Nobel laureate Gustaf Dalén invented the AGA in 1922, and it has been made ever since. It is a heat-storage cooker: a heavy cast-iron body holds heat, and food goes into ovens set at different temperatures rather than under a dial, so you cook by choosing the right oven and hotplate instead of adjusting a flame. That suits slow roasts, stews and a kettle always near the boil, and it warms the room. Electric and lower-energy models are now offered alongside the traditional shape. It is the biggest commitment on this list, in price, weight and running cost, and it rewards a household that cooks every day rather than once a week.