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Onion Relish is the kind of humble condiment that quietly steals the show, and this chunky tomato version is loaded with sauteed onions, Rotel, and warm Mexican spices. It is smoky, a little spicy, and exactly what a backyard hot dog has been missing, so Jason makes a double batch every time we fire up the grill. If you love a homemade topping like our bacon onion marmalade, this relish belongs in your fridge all summer.
One skillet and a little simmering turn a couple of onions and a can of Rotel into the best hot dog topping around.
Onion Relish Quick Look
- 🕒 Prep Time: 10 minutes
- 🌡️ Cook Time: 45 minutes
- ⏳ Total Time: 55 minutes
- 🍽️ Serving: 8 servings
- ⚡ Calories: 31kcal
- 🌶️ Flavor Profile: Smoky, savory, and a little spicy with sweet cooked onion
- ✋ Difficulty: Easy, on par with our homemade BBQ sauce
Quick Answer
Saute sliced yellow onion in olive oil until soft and browned, then stir in minced garlic and cook until fragrant. Add a can of Rotel along with paprika, cumin, oregano, salt, and pepper, and simmer uncovered until the liquid reduces. Cover and simmer a while longer so the flavors meld, then stir in fresh cilantro and serve warm or chilled.
Jump to:
Why This Recipe Works
Click to see the technique science
- Slow cooked onions turn sweet. Taking time to brown and soften the onions draws out their natural sweetness, which balances the tangy tomatoes.
- Rotel does double duty. Diced tomatoes with green chiles bring both the tomato base and a mild, smoky heat in one can.
- The spice blend is warm, not hot. Paprika, cumin, and oregano give the relish a cozy Mexican flavor without overwhelming spice.
- Simmering melds the flavors. A low, covered simmer at the end lets everything come together into one cohesive, jammy condiment.
- It keeps and reheats well. The relish only gets better after a day in the fridge, so it is perfect to make ahead for a cookout.
- It is naturally light. With just onions, tomatoes, and spices, a generous spoonful adds big flavor for very few calories.
Why You’ll Love This Recipe
- It turns plain hot dogs and brats into something craveable with one spoonful.
- It is a one skillet recipe made from pantry and produce staples.
- It keeps for days in the fridge and reheats easily, like our homemade BBQ sauce.
- It is light, smoky, and endlessly useful on tacos, nachos, eggs, and more.
Key Ingredients
Here is the short list of pantry staples that make this smoky tomato onion relish.
- Yellow onion: Sliced into rings and sauteed low and slow, it becomes the sweet, savory base of the relish.
- Rotel diced tomatoes: Tomatoes with green chiles add the tangy tomato base plus a gentle, smoky heat.
- Garlic and cilantro: Garlic adds savory depth while fresh cilantro brightens the finished relish.
- Paprika, cumin, and oregano: This warm spice trio gives the relish its cozy Mexican flavor.
- Olive oil: Just enough to saute the onions and carry all those spices.
See recipe card for exact quantities.
Variations and Substitutions
This relish is easy to adjust. Here are a few ways we like to change it up.
- Use red onion instead of yellow for a sharper bite and a touch more color.
- Add a diced jalapeno or a pinch of cayenne for extra heat.
- Stir in a spoonful of our sweet and spicy corn relish for a sweeter, chunkier mix.
- Swap the Rotel for plain diced tomatoes plus a diced green chile if you want to control the heat.
- Finish with a squeeze of lime for an extra bright, zesty version.
How to Make Onion Relish
- Saute the onion rings in the olive oil over medium heat until slightly browned and soft, stirring occasionally, about 10 to 15 minutes.
- Add the minced garlic, stir it in, and cook for about 30 seconds until fragrant.
- Add the Rotel, paprika, cumin, oregano, salt, and pepper, then simmer uncovered, stirring occasionally, until the liquid is reduced by half.
- Cover and continue simmering for about 20 minutes so the flavors meld, then stir in the cilantro and serve.
Recipe Tips & Tricks
- Slice the onions evenly so they cook and soften at the same rate.
- Do not rush the onions. Letting them brown low and slow builds the sweet, savory base of the relish.
- Drain the Rotel slightly if you want a thicker, chunkier relish with less liquid to cook off.
- Taste before serving and adjust the salt or a pinch more cumin to your liking.
- Add the cilantro at the end so it stays fresh and bright instead of cooking down.
- Store it in an airtight jar in the fridge for up to 5 days, and rewarm gently or serve cold.
Serving Ideas and Suggestions
This tomato onion relish is made for grilling season. Pile it high on hot dogs and brats, the way we do with our slow cooker beer brats, for a Mexican street food style bite.
Spoon it over burgers, tacos, nachos, or grilled chicken, or stir it into scrambled eggs for a smoky breakfast. A little goes a long way.
It is right at home on a cookout condiment table next to our homemade BBQ sauce and a jar of bacon onion marmalade so everyone can dress their plate.
Onion Relish FAQs
Onion relish is a savory condiment that is wonderful on hot dogs, brats, burgers, tacos, nachos, and grilled meats. This smoky tomato version is especially good piled on Mexican style hot dogs, and it even works stirred into eggs or rice.
Stored in an airtight container in the fridge, this onion relish keeps for up to 5 days. The flavor actually improves after a day, so it is a great make ahead condiment for a cookout.
It has a mild, smoky warmth from the Rotel green chiles and paprika, but it is not very spicy. For more heat, add a diced jalapeno or a pinch of cayenne. For less, use plain diced tomatoes instead of Rotel.
Yes. This relish is a perfect make ahead. Cook it, cool it, and store it in the fridge for up to 5 days, then serve it cold or gently rewarmed when you are ready.
Yes. Cool the relish completely, then freeze it in an airtight container for up to 3 months. Thaw it in the fridge and rewarm or serve cold. The texture stays nicely chunky.
Yellow onions are our go to because they turn sweet and mellow as they cook. Red onions work too for a sharper bite and more color, and sweet onions make an even milder, sweeter relish.
Love a good cookout topping? Try our jammy bacon red onion marmalade next.
Onion Relish
Ingredients
- 1 large yellow onion cut into 1/4 inch rings, skins removed
- 1 tablespoon olive oil
- 1 clove garlic minced
- 10 ounce can Rotel
- 1/4 up Cilantro rough chop, packed
- 1/2 teaspoon sweet paprika
- 1/4 teaspoon dried oregano
- 1 teaspoon ground cumin
- 1/2 teaspoon salt
- 1/2 teaspoon black pepper
Instructions
- Begin by sautéing onions with the olive oil over medium heat in a medium-sized pan. Cook until slightly browned and soft, stirring occasionally, 10-15 minutes.1 large yellow onion, 1 tablespoon olive oil
- Add in the garlic, stir it in, and cook for 30 seconds until fragrant.1 clove garlic
- Add in the Rotel and remaining ingredients. Cook uncovered on a simmer, stir occasionally, until the liquid is reduced by half, 5-10 minutes.10 ounce can Rotel, 1/4 up Cilantro, 1/2 teaspoon sweet paprika, 1/4 teaspoon dried oregano, 1 teaspoon ground cumin, 1/2 teaspoon salt, 1/2 teaspoon black pepper
- Cover and continue simmering for an additional 20 minutes so all the flavors can come together, stir occasionally. Serve as a condiment on many dishes!
Notes
- Saute onions until they are just beginning to brown for the best flavor.
- Let the relish cool to room temperature before storing.
- For a smoother relish, blend the mixture after cooking.
- Taste and adjust seasoning as you cook – everyone’s taste buds are different!
- Make a double batch – it’s so good you’ll want to have extra!
Nutrition
Love This Recipe?
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These hot dogs look amazing! When we lived in Tucson we found a great joint about a week before we moved to VA for sonoran hotdogs… needless to say I’ve been craving! I just pinned these and can’t wait to give them a try 🙂
These sound so delicious and easy to make! A great way to spice up dinner!
They look really good! Thanks for sharing on Sweet and Savoury Sundays, stop by and share with us again this weekend!
More cheese on mine please! These looks super yummy and make me hope summer is on it’s way!!
It’s still a bit to early to break out the snow covered grill, but this will definitely be on the menu this summer.
OOH! I could eat one of those right now for breakfast – thanks for the recipe!
This Spicy Tomato Onion Relish looks amazing! I bet it will be good on so many more things than hot dogs. I will be pinning this next. I am visiting today from Random Recipe Roundup. Have a great day!
oh my what a delicious hotdog could go for this anytime
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These look really tasty. I wouldn’t be able to get some of the same ingredients here but I will just settle for the inspiration and try and make something similar at some point – so much more tasty looking than just a hot dog!
Yum! That looks delicious! I cannot wait until it warms up here, at least a little so we can start grilling again.