Full credit and inspiration goes to the great YouTube channel Chinese Cooking Demystified. They obviously have a great video about this recipe, but I used their detailed written recipe as my primary inspiration for this recipe.
Part 1 - Aromatic Broth/Lushui (卤水)
150g Rhubarb
150g Onions
75g Ginger
180mL Soy Sauce
180mL Cooking Wine
1.8L Water
20g Cinnamon Bark
16-17g Star Anise (about 18-20 individual pieces)
15g Green Cardamom
15g Paprika
10g Dried Orange Peel
1.6-1.8g Cloves
Quickly fry aromatic vegetables in a small amount of oil, just 60 seconds. Deglaze with cooking wine, followed by soy sauce and water. Add spices and gently simmer for 45-90 minutes. Strain the liquid and measure the final yield, before cooling and transferring into a storage container. Refrigerate until needed
Part 2 - Char Siu Sauce
100% Aromatic Broth (previous mixture)
40% White Sugar
25% Red Miso (other homemade/artisan miso, if available)
15% Red Fermented Tofu/Liquid
10% Muscavado Sugar
10% Dextrose
20-40% Roasted Rhubarb
1% Gum Arabic
All ingredients for this next step are in a Baker’s percentage, based on the weight of the Aromatic Broth from Part 1. Start by measuring the rhubarb, 40% by weight based on the quantity of Aromatic Broth. Drizzle with a small amount of oil and roast in a 375°F oven. Checking every 5-10 minutes until soft and slightly colored, before setting aside.
Measure and combine the remaining ingredients, including the stock, into a medium-sized pot. Bring to a simmer and stir to dissolve the various sugars, continuing until it reduces just slightly (only by 10-20%).
Take the sauce off of the heat and add roughly half of the rhubarb, before blending thoroughly. Taste and add more rhubarb if desired, blending as necessary. Transfer into a clean jar, before cooling and refrigerating.