The dipping sauce for Sichuan hot pot (huo guo dian liao, 火锅蘸料) is as important as the broth itself — each diner builds their own individual dipping sauce at the beginning of the meal, adjusting the sesame paste, chilli oil, garlic, and aromatic additions to their preference. The function of the dipping sauce is partly to cool the scalding-hot items just removed from the broth, partly to add a contrasting flavour layer to the intense mala broth, and partly to personalise the experience. In Chongqing, the traditional dipping sauce is extremely simple (just sesame oil and garlic); in Sichuan broadly, the sesame paste-based bowl is the standard.
The Chengdu sesame paste bowl: The base sauce: 2 tbsp sesame paste (zhima jiang), thinned with hot water or hot broth from the pot to a loose, pourable consistency. Season with: 1 tbsp soy sauce, 1 tsp oyster sauce, 1 tsp sesame oil. Optional additions: raw minced garlic (important — the sharp pungency of raw garlic cuts through the richness of the fatty hot pot broth), Sichuan peppercorn oil, white vinegar or Chinkiang vinegar, small amount of doubanjiang, fermented tofu (nan ru), fresh coriander, thinly sliced fresh chilli, chilli oil. The Chongqing style: Much simpler — sesame oil + raw garlic only. The purity of the sesame oil against the intense mala broth is the point. Adding more to it complicates what is intentionally a simple contrast. The technique: The cooked hot pot ingredient is held above the dipping bowl for 2-3 seconds (allowing excess broth to drip off), then dipped quickly and briefly into the sauce — the sauce should barely coat the ingredient, not soak it.
Fuchsia Dunlop, The Food of Sichuan (2019); Fuchsia Dunlop, Land of Plenty (2001)