Subway Sweet Onion Sauce (Copycat)

"My reverse-engineered recipe for Subway's Sweet Onion Sauce, as requested by another member. It's quite sweet, but very tasty, if you've never tried it before."
photo by The Spice Guru photo by The Spice Guru
photo by The Spice Guru
photo by Ana W. photo by Ana W.
photo by altered.memos photo by altered.memos
Ready In:
1 cup




  • WHISK sauce ingredients together in a small saucepan (1 cup plus 2 tablespoons granulated sugar, 1/2 cup plus 1 tablespoon cold water, 6 tablespoons white vinegar, 1 1/2 tablespoons red wine vinegar, 1 tablespoon arrowroot powder, 1 tablespoon minced onion flakes, 2 1/2 teaspoons Dijon mustard, 2 1/2 teaspoons mustard powder, 3/4 teaspoon celery salt, 3/4 teaspoon fresh onion juice, 3/4 teaspoon poppy seeds, 1/2 teaspoon onion salt, 3/8 teaspoon garlic salt, 3/8 teaspoon paprika, 3/8 teaspoon black pepper, 1-2 drops sesame oil).
  • BRING mixture to a boiling while whisking constantly.
  • REDUCE heat to low simmer, stirring until thickened and flavorful, about 5 minutes.
  • ALLOW to cool, then refrigerate in a sealed container (keeps indefinitely).
  • SERVE as a dressing for sandwiches or salads and enjoy!

Questions & Replies

  1. How long would this recipe keep in the refrigerator?
  2. What is the nutritional values in percentages of this recipe


  1. this taste just like subway sweet onion..i might never go back to
  2. I use corn starch instead of arrowroot; and apple cider vinegar instead of red wine vinegar. Simple because that is what I have on hand and it is wonderful! I'm on my third batch.
  3. Tastes amazing just like subway will probably reduce sugar to 2/3 cup for personal preference.
  4. Thank you. Salad and more salad for me. Yesssssss
  5. Excellent recipe! I used cornstarch as I did not have arrowroot. I also subbed: 1 tsp Himalayan pink sea salt, 3/4 tsp celery seeds, granulated garlic and granulated onion instead of onion flakes nor all of the fancy salts I didn't have on hand. I used 2 tbsp sherry vinegar, 6 tbsp Bragg's apple cider vinegar, 3/4 cup organic cane sugar, smoked paprika, and just doubled up on dijon mustard instead of the mustard powder, and of course the 1/4 tsp poppyseeds. It's super sweet even with 3/4 cup of sugar so maybe I'll try 1/2 cup sugar next time. It's yummy. Thank you!
    • Review photo by Ana W.


Mathematician... Metaphysician... Magician in a test kitchen
View Full Profile

Find More Recipes