This is one of those extremely simple recipes that is a staple of its culture, yet it is so difficult to find an authentic recipe. I received this from someone who was born and raised in Sichuan province. Serve with fresh steamed white rice.
Peanut oil may be substituted for the soybean oil.
You can use ground beef instead of ground pork if desired.
Sichuan peppercorn is a rust-colored casing of a type of citrus fruit from China. It creates a unique sensation on the tongue and lips. It also mutes the piquancy of a dish, so more flavor comes through. Its flavor is lightly floral, citrus, and pine. Though there is no substitute for the sensation of the peppercorn, you can mimic the flavor with a mixture of coriander and cumin powder in a 2:1 ratio. When grinding the peppercorn, make sure there are no hard black seeds inside the peppercorn. They give the dish a gritty texture.
Doubanjiang is a red-colored sauce usually labeled 'chili-bean paste' and is very easy to get at any Asian grocery. Lee Kum Kee(R) makes a good paste and is widely available. They also make a 'Ma Po Sauce,' which is more or less the same and can be used in the same way.
You can reduce the oil if you are worried about the fat content, but it does have a purpose as a carrier for the chili flakes and Sichuan peppercorn, and it coats the mouth.