Sweet Onion Sauce Recipe

4.50 from 16 votes

The Sweet Onion Sauce inspired by the Subway sauce. You can use this condiment on things other than sandwich subs.

Prep Time5

Cook Time15

Total Time20

Course: Condiment

Cuisine: American

Servings: servings

Calories: 10kcal

Place the peeled onions, garlic, and water in a food processor or blender jar.
7 Small White Onion, 3 Medium Garlic Cloves, ¼ Cup Water
Mix the ingredients together until smooth.
Pour the smooth onion mixture into a sauce pan. Heat up your pan and keep on a slow heat setting.
Add the sugar and vinegar and mix well. Then season with black pepper and salt. Mix the content well.
½ Cup Sugar, ⅔ Cup Vinegar, ¼ Teaspoon Black Pepper Ground, ¼ Teaspoon Salt
Cook the sauce on slow heat until it gets translucent. That is a sign that it is cooked. Make sure to mix with a whisk frequently so to make sure that nothing burns on.
Mix cornflour and water to create a slurry. We need to do that because if you add the cornflour powder into the hot onion sauce directly, it will go lumpy.
1 Tablespoon Corn Starch, 3 Tablespoon Water
Whisk the whole content while heating up so that the sauce thickens. Keep it on the thicker side so that you can add the lime juice at the end.
Pour in your lime juice but don't heat it up again because the heat modifies the flavor of the lime juice.
Juice of one Lime
Store in a sterilized clean jar or sauce bottle in the fridge or in a cool and dry place.

7 small white onions = about 5.3 ounces or 150 grams
Pick a sweet onion variety and small young onions for the best result
For the vinegar, use a distilled or rice vinegar or us 50:50 balsamic and apple cider for a stronger flavor profile.
Always work with clean sterilized jars and lids to kill all the germs. That way, your sauce will remain good for a longer period in your fridge. Also, make sure your sauce cooked properly. Once it's translucent, it's a good sign.
The sugar in this sauce (besides the vinegar) helps the sauce to stay good without getting spoiled. Don't reduce the sugar amount!
Do not add more water. Water will reduce the shelf life of your sauce.
Cook the sauce to a thicker consistency if you prefer a thick sauce. However, remember, when the sauce is hot with the slurry added, it will always look more liquid and only when it cools down will you see how thick it gets.