A sweet-heat mustard sauce made with buttered onions, brown sugar, and smoked paprika – perfect on hot dogs, brats, and sausages.
This sweet hot onion mustard sauce takes a plain griddle hot dog from “fine” to “why haven’t I been making this the whole time.” It’s a mustard base loaded with buttered, softened onions, brown sugar, and just enough cayenne and crushed red pepper to give it some backbone. Sweet, tangy, a little smoky, a little hot – it’s not traditional anything, but it works on everything: hot dogs, brats, Italian sausages, even a grilled chicken sandwich.
The whole thing comes together in one pan in under 20 minutes, and it keeps in the fridge for whenever the next cookout rolls around.
*And be sure to check out our homemade hot dog chili for another fantastic hot dog condiment!
How to Make the Mustard Sauce
- Dice half an onion and sweat it in butter over low heat until soft and translucent – no color on it, just soft.
- Stir in the yellow mustard, dijon, brown sugar, cayenne, smoked paprika, vinegar, turmeric, and crushed red pepper.
- Let everything simmer together on low so the flavors combine and the sauce thickens slightly.
- Pull it off the heat, cool, and it’s ready to use or store.
Ways to Use It
- Spooned over a griddled hot dog, brat, or Italian sausage
- As a finishing sauce on a grilled chicken sandwich
- Swirled into a sausage and pepper skillet
- As a dipping sauce for pretzel bites or soft pretzels
- Mixed into a batch of deviled eggs for a sweet-heat kick
Sweet Heat Onion Mustard Sauce
Ingredients
- 2 tablespoons butter
- ½ medium yellow onion finely diced
- ½ cup yellow mustard
- ¼ cup dijon mustard
- 1 tablespoon white vinegar
- 2-3 tablespoons brown sugar
- ½-¾ teaspoon cayenne pepper
- ½ teaspoon smoked paprika
- ¼ teaspoon turmeric
- ¼ teaspoon crushed red pepper
Instructions
- Add the butter and diced onion to a small skillet or saucepan over low heat.
- Cook on low heat, stirring occasionally, for the onion to soften and become translucent, about 8–10 minutes. Keep the heat low so the onion softens instead of browning or caramelizing.
- Add the yellow mustard, dijon mustard, brown sugar, cayenne, smoked paprika, vinegar, turmeric, and crushed red pepper to the pan with the buttered onions.
- Stir everything together and let it cook on low for 5–7 minutes, stirring occasionally, until the sauce is heated through and slightly thickened.
- Remove from heat and let cool slightly before serving. Store leftovers in an airtight container in the fridge for up to two weeks.
How This Hot Dog Condiment Was Developed
This sauce started with a bottle of Koops Arizona Heat mustard we picked up at the grocery store. It’s a sweet heat mustard that, on its own is already incredible – tangy with a solid amount of heat. But we wanted to build a full hot dog experience.
Instead of just squeezing on the mustard straight from the bottle, we cooked down a batch of diced onions in butter – low and slow, so they stayed soft without browning – and stirred them right into the mustard. That one addition changed everything. The buttered onions mellowed the heat, added sweetness, and turned a good condiment into something that tasted like it had been simmering for hours.
This sweet heat mustard recipe takes it one step further, and uses basic pantry ingredients to create the hot dog (and maybe even pretzel) sauce from scratch. What began as a shortcut for a homemade hot dog condiment turned into a standalone sauce that’s now in regular rotation for hot dogs, brats, and sausages of every kind – no jar of specialty mustard required.
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