How to make that Hot Pot dipping sauce?

We cook hotpot at home all the time, and I barely miss eating at a restaurant. The good news is that every Chinese supermarket is fully stocked with hotpot gear.

The things to get are:

• A hotpot. There are different styles. I think we paid about 150RMB for a shallow-ish pot that sits on an electric hotplate. I've used the hotplate for other things, but it is specifically marketed as a hotpot hotplate.
• Hotpot Seasoning. This is the seasoning/sauce that is put in the boiling water and helps season whatever you put in the pot. There are a rainbow of flavours to choose from -- spicy, salty, seafood flavour, especially for lamb, etc. It comes in a package that looks like this. You usually wont need more than 1/3 to 1/2 of a package per hotpot.
• Dipping Sauce. This is called 火锅蘸料 and will be sold right beside the seasoning sauce. They are generally in little plastic containers that are joined together in sets of 2 or 4. They look like this.

Then all that's left is grabbing a variety of thinly sliced meats (usually sold in the freezer section of any large supermarket -- sometimes seasonal though), a bunch of wanzi (meat/seafood balls) and pretty much anything else you want to stick in it.

I realize that's probably a bit more info than you were looking for, but wanted to be thorough for anyone else that might stop by this question.

I also realize that I didn't technically answer you original question. If you wanted to make the sauce from scratch, it's somewhat tricky, as every hotpot restaurant has its own secret recipe (sometimes heavily guarded and coveted by competitors) for their sauces. Your base would most likely be sesame paste, then a variety of spicy chili, chili oil, garlic, a dash of cumin, some MSG/thick stock to loosen it up, salt, etc.

Hope it helps! Good eating!