In a mixing bowl, combine the peanut butter, soy sauce, and sugar. Stir until smooth and the sugar dissolves completely.
Add in the Chinese chive or cilantro, fermented soybean paste, and sesame oil. Mix thoroughly.
Add the minced garlic into the mixture and stir until well combined. The garlic will add an extra depth of flavor to the sauce.
Gently crush the Sichuan peppercorns using a mortar and pestle (or a rolling pin), and add them to the sauce for that signature numbing kick.
Pour in the chili oil and stir everything until smooth and evenly blended. Adjust the amount of chili oil based on your spice preference.
Let the sauce sit for a few minutes to allow the flavors to meld together before serving with your hot pot.