1. Put sesame paste, sugar, and salt in a preserving bottle, add soy sauce little by little and stir until smooth.

2. Cover softly with plastic wrap and microwave on 600W for 30seconds. (15seconds on 1200W)

3. Remove the wrap and screw top. Lasts for a month in a refrigerator.

*Without using microwave, put all the ingredients into a preserving bottle and stir until smooth. Pour water to 5mm depths in a pot, bring to the boil and turn off the heat. Soak the bottle in the hot water for 1minute to help the seasonings to mix well.

For how long you should cook with your microwave oven, see Cooking Time vs Wattage Conversion.
For more tips of using Microwave Oven, see Sachiko's Guideline to Microwave Cooking.