The other difference is in the stock. You can almost immediately tell which region the chef is from by looking at the stock that comes to the table.

In Beijing, the stock is clear, almost tasteless. You are expected to flavor it as you cook the meat. No one takes a sip until the meal is halfway through.

There is another northern version where lamb shanks are cooked in a spicy thick broth. This is known as "scorpion bones", yangxiezi. Tofu, meatballs and other products are dunked in to cook as the broth bubbles away. This hearty hotpot is a grassroots favorite and especially popular in the hutong restaurants, where regular diners prefer heavily seasoned dishes.

But if you are talking about spicy soup stocks, nothing beats the Chongqing or Chengdu hotpots. Spadefuls of fiery chili peppers and Sichuan peppercorns are fried up with other spices in plenty of rendered beef fat and poured onto a light stock.

This creates a 3-centimeter-thick layer of oil and chili on top of the stock in a simmering cauldron of spicy lava. A quick dip into that quickly cooks the meat, or whatever innards the Sichuan gourmets are so fond of.

One of the most famous hotpot brand names to come out of Sichuan is the Haidilao franchise. The chain has perfected the hotpot formula, with excellent and showy service and comfortable holding areas while you wait for your table.