Sweet Onion Sauce is my take on the onion sauce that you get at Subway.
I have modified the sauce so that it can be used beyond subs and sandwiches.
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TL;DR
I call my Subway Sweet Onion Sauce a fake copycat recipe because it's used as a topping for subs.
I have modified the ingredients used and the looks to make it rather mild but smooth as well and not that dominating.
This sauce can be used for other dishes as well, and its uses are not limited anymore!
The popular Sandwich food chain Subway uses (most probably) dark vinegar such as balsamic vinegar to add the strong sub-flavors.
I, on the other hand, use rice vinegar to give it a subtle feel so that the vinegar doesn't overpower the mild white onions.
Ingredient Notes
Sweet Onion Sauce Ingredients include only fresh ingredients and is prepared with a natural preservation technique. Vinegar and Sugar help to preserve the Sauce.
- White Onions — Pick a sweet, young and small variety of white onions. Those tend to be milder but turn out more flavorful as well.
- Garlic — You can't skip the garlic, it adds flavors and helps the sauce to preserve.
- Sugar — You can choose between regular sugar or brown sugar if you feel adventurous. Sugar helps to balance out the flavors, and especially the tart vinegar.
- Vinegar — An essential element of the sweet onion sauce. Pick a white mild vinegar such as rice vinegar or regular distilled vinegar.
- Salt & Black Pepper — Salt and Black Pepper for the flavor, and the Pepper adds some texture too because the sauce is translucent.
- Corn Flour — A slurry is a mixture of cornflour and water to thicken the sauce.
- Lime Juice — The Lime Juice adds a fresh touch to the juice, and it lifts all the flavors in the sauce.
How to make it?
To prepare this sandwich sauce is fairly simple.
Step 1
Blend peeled onions + garlic with water smooth.
Step 2
Cook onion blend with vinegar, sugar, and seasoning.
Step 3
Create a slurry with cornflour and water and mix into the sauce. Mix in lemon juice, store in a jar.
📖 Recipe
Sweet Onion Sauce Recipe
Ingredients
- 7 Small White Onion
- 3 Medium Garlic Cloves
- ¼ Cup Water
- ½ Cup Sugar
- ⅔ Cup Vinegar *see Note
- ¼ Teaspoon Black Pepper Ground
- ¼ Teaspoon Salt
- Juice of one Lime
For the Cornflour Slurry
- 1 Tablespoon Corn Starch
- 3 Tablespoon Water
Instructions
- 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.
Notes
- 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.
Nutrition
Storing
As you can see, you don't need special bottles to store this sweet onion sauce.
I like to store my sauces in bottles but if I am out of bottles but need sauce (and that turns into a craving) I am bound to just prepare my sauce and store it in clean sterilized regular jam jars.
No judgment and it does the job as well! So you can just grab your usual jars which you use to make jam and fill it up with the sauce.
To take out the sauce, I just use a spoon and because it is a short jar, I can easily find a spot to store my fake subway sauce in my fridge.
I tend to avoid bottles because they take up my precious door space and I don't like to lie down bottles.
Uses
- Classic in Subs, Sandwiches
- As a dipping sauce for cooked meat, veggies, fried potato dishes
- As a Sweet Onion Dressing Vinaigrette
- In soups as a garnish
- In Mash Potato
More homemade Sauce Recipes:
I've used this sauce as a stir fry sauce for beef pork and venison with good results. It's a great dipping sauce for all kinds of fries.
Thanks for sharing Tammy. 🙂