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Mouthwatering Sweet Onion Sauce Recipe

Category: Snacks That Bring People Together

DIY version of Subway’s sweet onion sauce. Done in just 15 minutes, and it keeps for 7 days in the fridge.
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By Sophie Parker Sophie Parker
Updated on Fri, 07 Mar 2025 01:07:47 GMT
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Savory Homemade Onion Sauce | tastybysophie.com

Creating a homemade sweet onion sauce has become my latest kitchen obsession. After extensive testing and refinement, I've developed a recipe that perfectly captures that beloved sandwich shop flavor while adding fresh, natural ingredients that take it to the next level.

This sauce has become indispensable in my weekly meal prep. The homemade version offers brighter flavors and more nuanced complexity than the original.

Key Ingredients

  • Sweet Onion - Vidalia or Walla Walla varieties provide ideal mild sweetness
  • Vinegar Blend - Red wine and white vinegars create balanced acidity
  • Toasted Sesame Oil - Adds subtle depth and complexity
  • Fresh Ground Spices - Maximum flavor potency
  • Cornstarch Slurry - Achieves perfect sauce consistency
Homemade Subway Sweet Onion Sauce Recipe Save
Homemade Subway Sweet Onion Sauce Recipe | tastybysophie.com

Essential Preparation Tips

1.
Use a microplane grater for the onion to achieve a smooth, nearly liquid consistency. A standard grater's finest holes work as an alternative.
2.
Gently warm vinegars before combining with sugar - this ensures proper dissolution and flavor development.
3.
Maintain gentle heat when cooking. A slow simmer yields ideal texture; rapid boiling can overly thicken the sauce.

Technique Refinements

* Select fresh poppy seeds for optimal flavor
* Mix cornstarch with cold water before adding to prevent clumping
* Allow complete cooling before storage for proper thickening

Troubleshooting Guide

* For overly thick sauce, incorporate warm water gradually
* To thicken, add additional cornstarch slurry while warm
* Adjust acidity with small additions of vinegar

Versatile Applications

This sauce extends far beyond traditional sandwich use. Here are tested applications that showcase its versatility:

Sandwich Alternatives

* Baste grilled poultry during final cooking minutes
* Enhance roasted root vegetables
* Incorporate into seafood salads
* Finish artisan pizzas

Protein Applications

* Glaze baked salmon
* Marinate shellfish
* Accent grilled meats
* Enhance egg preparations

Salad Enhancements

* Dress roasted vegetable medleys
* Create unique pasta salads
* Season grain bowls
* Prepare Asian-inspired slaws

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Easy Homemade Subway Sweet Onion Sauce | tastybysophie.com

Appetizer Ideas

* Complement crispy fried foods
* Top loaded potatoes
* Season air-fried vegetables
* Create unique spreads

Entertaining Options

* Finish vegetable platters
* Accompany Asian appetizers
* Season grilled corn
* Enhance burger preparations

Creative Uses

* Incorporate into egg dishes
* Glaze roasting vegetables
* Finish specialty pizzas
* Season potato dishes

Storage Guidelines

Optimal storage practices include:
* Use clean dispenser bottles
* Store in refrigerator's main compartment
* Allow brief warming if over-thickened

Recommended Combinations

Tested pairings include:
* Turkey-avocado combinations
* Enhanced cabbage slaws
* Root vegetable accompaniments
* Fresh vegetable preparations

Concluding Notes

This sauce has evolved beyond mere replication to become a versatile kitchen staple. Each batch presents opportunities for new culinary applications.

The recipe framework allows for personalization - modify sweetness and acidity levels according to preference.

Sweet Onion Dip

Bring Subway’s signature sweet onion sauce to your kitchen with this simple homemade recipe. A perfect mix of sweetness and tang!

Prep Time
5 min
Cook Time
10 min
Total Time
15 min
By Sophie Parker: Sophie Parker

Category: Party & Snacks

Skill Level: Beginner

Cuisine: American

Yield: 8 Servings (2 cups)

Dietary Preferences: Vegan, Vegetarian, Gluten-Free, Dairy-Free

Ingredients

→ Main Ingredients

01 1 cup of granulated sugar
02 Half a cup of water
03 6 tablespoons of plain vinegar
04 1 1/2 tablespoons of red wine vinegar
05 1/2 tablespoon of freshly grated onion
06 1 tablespoon of cornflour
07 2 teaspoons of smooth Dijon mustard
08 2 teaspoons of dry mustard powder

→ Seasonings

09 1 teaspoon of poppy seeds
10 1/2 teaspoon of sesame oil
11 1/2 teaspoon of powdered onion
12 1/2 teaspoon of salt
13 1/4 teaspoon of garlic powder
14 1/4 teaspoon of celery seed
15 1/4 teaspoon of paprika powder
16 1/4 teaspoon of ground black pepper

Steps

Step 01

Throw everything into a saucepan.

Step 02

Heat it up to a boil, whisking constantly. Let it boil for 5 minutes, then drop the heat to simmer for another 5 minutes while still whisking.

Step 03

Take the pan off the heat and let it cool down. Pour into an airtight container and keep it in the fridge for as long as a week.

Notes

  1. You can cut down on sugar or swap it with another sweetener if you'd like
  2. This works perfectly as a salad dressing or as a marinade
  3. The sauce thickens as it cools down

Required Tools

  • A saucepan
  • Whisk
  • Measuring tools (cups and spoons)
  • A grater or microplane

Allergy Information

Check each ingredient for potential allergens and consult a healthcare professional if needed.
  • Sesame (since it uses sesame oil)
  • Mustard (from Dijon and mustard powder)

Nutritional Facts (per serving)

These details are provided for informational purposes and aren't a substitute for medical advice.
  • Calories: ~
  • Fats: ~
  • Carbohydrates: ~
  • Proteins: ~