As I know, Sichuan sweet bean paste is usually used for cold dish. One version is made from fermented wheat powder and taste "sweet" for Sichuanese, but no sugar and no chili added at all.
It is really complicated. All you need are meat, firm tofu, douban jiang (board bean paste), sichuan peppercorn powder, starch. dry pepper if spicy.
A key secret is tofu becomes tender when heated with salt. and eat tofu in hot.
board bean paste is the key for this recipe. you can find it at http://PosharpStore.com for different brand on your favors.