Sweet Burger Relish With Tomatoes
This sweet tomato relish is a brilliant burger topping that’s packed with flavour and easy to make at home. Using canned tomatoes, onions, vinegar, and a handful of extras like capers and gherkins, it simmers down into a thick, tangy relish that’s just right for burgers, wraps, or even a cheese toastie.
Recipe Overview
Skill Level:
BEGINNER
Prep Time:
10 MINUTES
Cook Time:
60 MINUTES
What Makes This Recipe Great
Perfect for Burgers: This burger relish is sweet, tangy, and just the right texture for spooning onto burgers, hot dogs, or sandwiches.
Uses Store Cupboard Ingredients: Made mostly from tins and pantry basics, so it’s easy to throw together.
Keeps Well: Ideal for batch cooking and storing in jars to use throughout the week.
This sweet burger relish is one of those easy recipes that instantly makes homemade burgers feel like something special. It’s rich, tangy, and packed with flavour from slow-simmered tomatoes, red wine vinegar, and a little kick of chilli. The chopped gherkins and capers stirred in at the end give it a lovely contrast in texture, and it works just as well spread on a bun as it does served on the side. A homemade condiment that’s great for barbeques as it pairs well with grilled meats and is perfect for burgers. You can even use it as a dipping sauce for chicken or fries.
If you enjoy making your own burger toppings, this is a great one to have in the fridge—right alongside other favourites like this Caramelised Onion Chutney, Jalapeño Chilli Jam, or even a spoonful of Autumn Chutney. We love it on Nacho Burgers or served with Cheeseburger Loaded Fries as part of a fakeaway-style dinner.
It keeps well in the fridge, so it’s worth making a batch—you’ll find yourself reaching for it again and again.
Equipment Needed:
- Large Saucepan: Use a deep, non-reactive saucepan (avoid uncoated aluminium) for simmering the relish—this helps prevent any metallic taste from the vinegar.
- Sharp Knife and Chopping Board: For prepping the onion, chilli, garlic, gherkins, and coriander.
- Wooden Spoon or Silicone Spatula: For stirring regularly as the relish cooks down to a jammy consistency.
- Sterilised Jars or Airtight Containers: To store the cooled relish—glass jars or containers with lined lids work best for anything vinegary.
Ingredients:
- Olive Oil: For gently softening the onion and forming the base of the relish.
- Yellow Onion: Sliced thinly and cooked slowly to bring out the sweetness.
- Garlic Clove: Crushed and added for background flavour—nothing too strong.
- Red Chilli: Adds a gentle heat—feel free to adjust the amount depending on your preference.
- Canned Chopped Tomatoes: Easy and convenient, these make up the bulk of the relish and it’s easier and more convenient than fresh tomatoes for this recipe.
- Red Wine Vinegar: Adds sharpness and balances the sweetness—don’t swap for malt or white vinegar.
- Granulated Sugar: Gives the relish its signature sweetness and helps create a sticky, jammy texture.
- Capers: Rinsed to remove excess salt and stirred in at the end for a savoury, tangy bite.
- Baby Gherkins: Chopped finely to give little bursts of texture and flavour.
- Fresh Coriander: Stirred in just before cooling for a fresh lift.
- Sea Salt and Freshly Ground Black Pepper: Added at the end to season to your taste.
Substitutions and Additions:
Wondering if you can substitute or add an ingredient? Here, I will tell you if that’s possible.
Substitutions
- Red Chilli: Swap for chilli flakes or red pepper flakes or leave it out entirely if you prefer a milder relish.
- Yellow Onion: White or red onion will also work—yellow just gives the best balance of sweetness.
- Granulated Sugar: Caster sugar will work too, or light brown sugar for a slightly deeper flavour. You can also use honey if you’d prefer.
- Capers: If you don’t have capers, try using a few extra chopped gherkins for a similar tangy hit.
- Fresh Coriander: Leave it out if you’re not a fan, or replace with a small handful of chopped fresh parsley.
Additions
- Mustard Seeds: Add a teaspoon early on with the onions for a light pickled flavour and extra texture.
- Smoked Paprika: Stir in a pinch with the garlic for a subtle smoky edge.
- Extra Chilli: If you like it hot, double up on the red chilli or add a splash of hot sauce at the end.
Step-By-Step Guide – How To Make Sweet Burger Relish With Tomatoes
Frequently Asked Questions
Yes, but you’ll need to cook them down for longer. Peel and chop them first, and make sure they’re ripe for the best flavour.
It has a mild warmth from the red chilli, but it’s not overly hot. You can leave the chilli out or add more depending on your preference.
This relish is best left chunky, so blending isn’t necessary. If you prefer it smoother, you can pulse it very briefly once cooled.
It’s similar in cooking style, but this relish is a bit looser and less intensely sweet than a traditional chutney.
Definitely. Just use a large enough pan and allow more time for the relish to reduce and thicken.
Mastering This Recipe – Expert Tips
- Slice the Onion Thinly: The thinner the slices, the quicker they’ll soften and break down into the relish.
- Cook the Onions Gently: Don’t rush the base—taking your time here gives the relish more natural sweetness.
- Taste Before Cooling: Flavours settle as the burger relish cooks, so adjust salt, sugar, or vinegar while it’s still hot.
- Avoid Uncoated Aluminium Pans: The vinegar can react with certain metals—go for stainless steel or non-stick instead.
Storage
- Fridge: Once cooled, transfer the relish to sterilised jars or airtight containers. It will keep in the fridge for up to 2 weeks.
- Canning (for longer storage): If you’re comfortable with water bath canning, you can preserve the relish for several months. Use sterilised jars with new lids, fill while the relish is hot, and process according to safe canning guidelines. Store in a cool, dark place and refrigerate once opened.
- Freezing: The relish can be frozen. Let it cool completely first, then freeze in small containers or freezer bags. Freeze for up to 3 months.
- Defrosting: Defrost in the fridge overnight or at room temperature for a few hours. Stir well before serving.
Sweet Burger Relish With Tomatoes
Ingredients
- 1 tbsp Olive Oil
- 1 Yellow Onion, thinly sliced
- 1 Garlic Clove, crushed
- 1 Red Chilli, deseeded and finely chopped
- 800 g Canned Chopped Tomatoes
- 200 ml Red Wine Vinegar
- 200 g Granulated Sugar
- 30 g Capers, rinsed
- 4 Baby Gherkins, finely chopped
- A handful of Fresh Coriander, chopped
- Sea Salt and Freshly Ground Black Pepper, to taste
Instructions
- Heat the olive oil in a large saucepan over medium heat.
- Add the sliced onion and cook gently for about 5–7 minutes until soft and translucent.
- Stir in the crushed garlic and chopped red chilli and cook for another minute.
- Pour in the chopped tomatoes, red wine vinegar, and sugar. Stir well to combine.
- Bring the mixture to a boil, then reduce the heat to low and let it simmer uncovered for around 45–60 minutes, stirring occasionally, until thick and jammy.
- Stir in the rinsed capers, chopped gherkins, and coriander during the final 5 minutes of cooking.
- Season to taste with sea salt and freshly ground black pepper.
- Remove from the heat and let the relish cool before transferring it to jars or containers.
Recipe Notes
- Use a wide pan: This helps the relish reduce faster and gives a thicker, jammy texture.
- Adjust the spice: Add more or less chilli depending on how much heat you like.
- Finely chop the extras: Chopping the capers and gherkins small helps them blend into the relish without big chunks.
- Best served chilled or room temperature: Let it cool fully before using for the best flavour and texture.
- For longer storage: Consider canning the relish using a water bath method to keep it shelf-stable.
