Finely chop the onion and garlic.
In a bowl, mix the measured amounts of red pepper powder, erythritol, soybean paste, soy sauce, vinegar, and water.
Add the chopped onion and garlic, then mix well.
Place the mixture in a pan over medium-low heat and simmer while stirring for 5–10 minutes.
Let the finished low-sugar gochujang cool, then store it in a container.