One example would be a cooktop and electric oven. I have one that connects to 3-phases. On the cooktop, the left and the right sides are each connected to their own phase. You can run both sides at 2,600 watts max at the same time. In the oven, there are 3 heaters: top, bottom, and one inside the fan; each connected to one of the phases. Together they can reach about 10,000 watts. The oven has a heat-up program that uses all 3 heaters to reach the temperature you've set.

Overall, it can heat things up more quickly than a typical gas or electric stove while being more efficient. And you can quickly change the temperature like with a gas stove.