The most likely ingredient is **Sichuan peppercorn**, also spelled *Szechuan pepper* and called **花椒 (huājiāo)**.

Your “ants with hot feet” description fits its distinctive buzzing, prickling sensation remarkably well. Its active compound, **hydroxy-alpha-sanshool**, stimulates touch-sensitive nerves; researchers found that people compared the resulting tingle to a vibration of about 50 Hz. That explains why it feels like many tiny points of stimulation. [Research on Sichuan pepper’s tingling](https://pmc.ncbi.nlm.nih.gov/articles/PMC3779329/)

Combined with chillies, it produces **málà (麻辣)**—“numbing and spicy.” To find that experience again, look for Sichuan peppercorns or dishes described as *mala*. [Mala seasoning](https://en.wikipedia.org/wiki/Mala_%28seasoning%29)

The restaurant could have been **TamJai SamGor**: its cartoon mascot and spicy noodle soups fit your clues, though that identification is tentative. Its menu includes a “Hot & Numbing” mala soup. [Company prospectus](https://tamjai-intl.com/wp-content/uploads/2021/09/2021092300031.pdf)