Add the ground spice mixture, reserved marinade, brown sugar, salt, water, bay leaf, and cardamom pod to the ground pork and stir to combine. Bring to a simmer over medium-high heat, then reduce the heat to medium and simmer, stirring occasionally, until the meat is no longer pink, about 15 minutes. Reduce the heat to low, cover, and simmer until the flavors have melded, about 2 hours, stirring every half hour. Meanwhile, place the vinegar, garlic, ginger, tomato paste, fermented black beans, and soy sauce in a medium bowl and stir to combine; set aside.4When the pork is ready, remove from heat, add the reserved black bean mixture and the mushrooms, and stir to combine. Taste and season with chile oil, additional soy sauce, brown sugar, and black or white vinegar as needed to balance the flavors. (At this point, you can cool the sauce completely, then transfer it to a container with a tightfitting lid and freeze it for up to 1 month.)To serve:1