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If you love Subway's sweet onion sauce, you'll be delighted to find we've discovered the secret! This tasty condiment transforms every sandwich into a flavor sensation, thanks to a delicate and fantastic balance of sweet and savory.
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Subway Sweet Onion Sauce Recipe

If you love Subway's sweet onion sauce, you'll be delighted to find we've discovered the secret! This tasty condiment transforms every sandwich into a flavor sensation, thanks to a delicate and fantastic balance of sweet and savory.
Prep Time 10 minutes
Cook Time 6 hours
Total Time 6 hours 10 minutes
Servings 16

Ingredients

  • ¼ cup sugar granulated
  • ¼ cup water
  • ¼ cup white vinegar
  • 1 tablespoon sweet yellow onion finely grated or pressed
  • 1 tablespoon red wine vinegar
  • 1 tablespoon onion powder
  • ½ teaspoon garlic powder
  • 2 teaspoons dijon mustard
  • 2 teaspoons mustard powder
  • ½ teaspoon paprika
  • ¾ teaspoon celery salt
  • 1 teaspoon poppy seeds
  • ¼ teaspoon sesame oil optional
  • salt and pepper to taste

Instructions

  • In a small microwaveable bowl, add the sugar and water.
  • For one minute, microwave on full power, whisking several times until dissolved.
  • Toss in the rest of the ingredients and whisk until combined.
  • If you find the mixture is too thick, add a few drops of water and whisk to combine. If the mixture is quite thin, you may add a dash of onion powder and mustard powder.
  • Store in a mason jar in the fridge for up to one month. Use on sandwiches, burgers, and in other recipes.

Notes

  • If stored correctly (in a sealed container or jar in the fridge), this sauce will last up to one month.
  • You can also make sweet onion sauce keto-friendly by substituting the sugar with a low-carb sweetener, where 1 cup of sweetener is equivalent to 1 cup of sugar.