Sweet Onion Teriyaki Sauce (Subway Copycat)

Sweet onion teriyaki sauce is the sticky, tangy glaze that made Subway’s chicken teriyaki sub so popular, and you can make your own version on the stove in about 15 minutes.

It turns a plain grilled chicken breast, a bowl of rice, or a stack of roasted vegetables into something you actually look forward to eating.

Why I Love This Recipe

This sauce hits sweet first, then the soy saltiness catches up right behind it, with just enough rice vinegar to keep things from tasting like syrup.

The minced onion cooks down soft and nearly melts into the glaze, so you get real onion flavor without chunks getting stuck in your sandwich.

It thickens fast once the cornstarch goes in, so you’re not standing at the stove waiting around for it to happen.

Recipe Ingredients

• 1 tbsp (15ml) vegetable oil – or any neutral oil, for softening the onion
• 1/2 cup (75g) sweet onion, finely diced – Vidalia or Walla Walla if you can find one, for that mellow onion flavor
• 2 cloves garlic, minced – fresh, not the jarred kind, for a cleaner bite
• 1/2 tsp ground ginger – warms up the background flavor
• 1/2 cup (120ml) soy sauce – regular, not low sodium, gives the sauce real backbone
• 1/2 cup (100g) granulated sugar – the sweetness that defines this sauce
• 1/4 cup (60ml) rice vinegar – keeps the sweetness from tipping over into syrup
• 3/4 cup (180ml) water – thins the base before it reduces
• 1 tbsp cornstarch – thickens the sauce into a glaze
• 2 tbsp (30ml) cold water – whisked with the cornstarch into a slurry
• 1 tsp toasted sesame seeds – optional, for garnish

Variations / Substitutions

• Protein swap – brush this over salmon or pork chops instead of chicken; the sugar caramelizes nicely on both under a broiler.
• Sweetener swap – use 1/2 cup honey instead of the granulated sugar for a deeper, slightly floral sweetness, though the sauce will run a bit thinner.
• Herb addition – stir in 1 tbsp sliced scallion right at the end for fresh color and a mild bite.
• Spice or heat – add 1/4 tsp red pepper flakes with the garlic and ginger if you want it to bite back a little.
• Dairy-free – this sauce is naturally dairy-free as written, no changes needed.
• Acid swap – apple cider vinegar works in place of the rice vinegar if that’s what you have, and it gives a sharper edge.

If you like sticky glazes like this one, my Honey Garlic Chicken Bowls recipe uses a similar base.

How To Make Sweet Onion Teriyaki Sauce

Step 1: Soften the Onion

Heat the 1 tbsp vegetable oil in a small saucepan over medium heat. Add the 1/2 cup diced sweet onion and cook, stirring every minute or so, for about 4 minutes, until it turns soft and translucent with a few golden edges. Stir in the 2 cloves minced garlic and 1/2 tsp ground ginger and cook for 30 seconds, just until fragrant.

You’ll know it’s ready when the onion has gone glassy and your kitchen smells like garlic and warm ginger. Don’t rush this part, the onion needs to actually soften here or it’ll stay crunchy in the finished sauce.

Step 2: Simmer the Sauce Base

Pour in the 1/2 cup soy sauce, 1/2 cup granulated sugar, 1/4 cup rice vinegar, and 3/4 cup water. Stir well to dissolve the sugar, then bring the mixture to a gentle simmer over medium heat, about 3 minutes.

Small bubbles should form around the edge of the pan, and the sauce will darken to a deep amber as it simmers. Give it a stir now and then so nothing scorches on the bottom.

Step 3: Thicken the Glaze

In a small bowl, stir the 1 tbsp cornstarch into the 2 tbsp cold water until smooth, then pour it into the simmering sauce. Stir constantly and let it simmer for about 2 minutes, until the sauce turns glossy and coats the back of a spoon.

It thickens fast here, almost like watching syrup form in real time. If it ever looks lumpy, keep whisking over the heat, it smooths right back out.

Step 4: Pour and Garnish

Remove the pan from the heat and pour the sauce into a small glass jar or a shallow bowl. Scatter the 1 tsp toasted sesame seeds over the top while it’s still warm and glossy.

The sauce should look deep amber with tiny flecks of onion throughout, thick enough to cling to a spoon but still pourable. Let it cool for a few minutes before you brush it on anything, it holds heat longer than you’d expect.

Recipe Tips

• If the sauce seems too thin right after cooking, don’t worry, it thickens more as it cools in the fridge.
• Taste the sauce before you add the cornstarch slurry, since it’s much easier to adjust sweetness or salt while it’s still thin.
• For the smoothest texture, pulse the onion in a food processor a few times instead of hand dicing it.
• This recipe doubles well and keeps for weeks, so it’s worth making a full batch even if you only need a little tonight.

Simmer times by batch size:

Batch Size	Sauce Base Simmer	Thickening Simmer
Single (this recipe)	3 minutes	2 minutes
Double batch	5 minutes	3 minutes

How To Store

Refrigerate: Keep the sauce in an airtight jar in the fridge for up to 3 weeks. The soy sauce and sugar act as natural preservatives, so it holds up well.

Reheating: If it’s too thick to pour straight from the fridge, warm it in the microwave in 15-second bursts, or in a small saucepan over low heat, stirring until loosened.

Serve Cold: You can also use it straight from the fridge on cold sandwiches or salads without warming it at all.