Sauté the Aromatics
Heat 1 teaspoon cooking oil in a small saucepan over medium heat.
Add 1 teaspoon finely minced garlic to the pan.
Gently sauté garlic for about 30 seconds until it’s fragrant. Be careful not to burn the garlic, as this can make the sauce taste bitter.
Add Fermented Black Soybean Paste
Add 3 tablespoons fermented black soybean paste to the pan.
Cook gently for 1-2 minutes, stirring continuously to mix well with the garlic. This helps develop a richer flavor.
Combine Remaining Ingredients
Add 2 tablespoons hoisin sauce, 1 tablespoon smooth peanut butter, and 1 teaspoon sugar to the pan.
Slowly pour in ½ cup (120 ml) water, stirring carefully until everything blends smoothly together.
Simmer and Thicken
Reduce the heat to low and let the sauce simmer gently for about 3–4 minutes, stirring regularly until the sauce becomes slightly thicker and smoother.
Finish and Serve
Remove the pan from heat and let the sauce cool slightly.
If you like, sprinkle 1 tablespoon crushed roasted peanuts and add a small spoonful of chili paste or sliced fresh chili on top to make it extra tasty.