Piquant, sweet and savory, this mustard relish quickly became a favorite condiment. Bright from mustard powder and mustard seeds, its sunny yellow color is complemented by crunchy summer vegetables like cucumber, bell pepper and red onion. Spoon it over a hot dog, spread it on a sandwich made with sourdough, or serve it alongside cheeses — the balance of tang and sweetness makes it versatile and delicious.
Why You’ll Love This Recipe
Two condiments in one – If you enjoy classic yellow mustard and cucumber relish, this combines both into a single, textured condiment with the right mix of sweet and tang.
Quick and easy – A food processor does the chopping, then a short simmer and a chill in the fridge finish the recipe. It’s fast and low-effort.
Uses extra summer produce – Great for using up a bumper crop of cucumbers. You can also swap in zucchini or summer squash if you prefer.
Ingredients
- Cucumbers – English cucumbers work well; peel thick-skinned varieties if you like.
- Red bell pepper – Gives a sweet crunch and a pop of color. Yellow or orange peppers also work.
- Red onion – Adds bite and color; any onion will do if you prefer.
- Salt
- White vinegar – Affordable and sharp; cider vinegar is an acceptable substitute.
- Sugar – Granulated white sugar balances the acidity.
- Mustard powder – Also called dry or ground mustard.
- Mustard seeds – Yellow seeds keep the color bright; black seeds are fine too.
- Ground turmeric – Adds earthy flavor and enhances the golden hue.
How to Make Mustard Relish
This relish is made by finely chopping the vegetables, drawing out moisture with salt, and simmering everything in a mustard-spiked vinegar syrup. The result is a chunky, spreadable relish with bright flavor.
Add the trimmed cucumber, bell pepper and onion to a food processor and pulse to a fine dice. Take care not to over-process — you want texture, not a puree.
Transfer the chopped vegetables to a large colander placed over the sink, sprinkle with salt, stir, and let drain for at least 30 minutes. Expect a lot of liquid to run out.
While the vegetables drain, combine the vinegar, sugar, mustard powder, mustard seeds and turmeric in a pot. Bring to a boil, then reduce heat and simmer for 5–10 minutes to soften the mustard seeds. If the vegetables need more time, turn the heat off and keep the mixture warm.
Kate’s Pro Tip
Using turmeric and mustard powder
Turmeric and mustard powder can stain, so avoid using prized white or wooden utensils if you don’t want faint yellow discoloration.
Prepare jars for storage by pouring boiling water into them and letting them sit, or run them through a hot dishwasher cycle to sterilize.
When the vegetables have drained, add them to the pot and stir to combine. Bring the mixture back to a boil, then simmer for another 5–10 minutes or until you reach the texture you prefer. The relish should be thick enough to scoop and spread while the vegetables keep a bit of bite. Adjust seasoning with extra salt, sugar or mustard powder to taste.
Use a funnel and ladle to fill sterilized jars, leaving about 1 cm of headspace. Seal while hot, let the jars cool on the counter, then refrigerate.
How to Use Mustard Relish
This relish is perfect on sandwiches made with sourdough rolls, as a topping for grilled hot dogs or burgers, and as a bright accompaniment on cheese boards. It pairs especially well with cured meats, sharp cheddar and crunchy crackers.
Try it inside a sandwich with ham or turkey, cheddar, lettuce and a generous spoonful of relish for a flavorful lunch. It also livens up a grilled cheese or acts as a colorful addition to a ploughman’s platter.
How To Store + Freeze
Stored in an airtight container, the relish will keep about a week in the refrigerator. In sterilized, sealed jars it can last a few months in the fridge. You can also freeze the relish—leave room in the jar for expansion or use freezer-safe containers.
Frequently Asked Questions
Yes. You can swap some cucumber for zucchini or summer squash, and change the bell pepper or onion variety. Keep the overall quantities similar for best results.
Cook until enough liquid has evaporated and the mixture has thickened slightly. The relish should be scoopable and spreadable while the vegetables retain some bite.
A relish is a condiment of chopped fruits or vegetables preserved or cooked with vinegar and sugar to create a sweet-and-sour, chunky accompaniment. It’s generally chunkier than chutney and more preserved than a fresh salsa.
Mustard Relish
Rate Recipe
Print Recipe
Equipment
- Food processor
- Storage jars (three 300 ml jars recommended)
Ingredients
- 2 English cucumbers (about 650 g once trimmed)
- 1 red bell pepper (about 140 g once trimmed)
- 1 red onion (about 120 g once trimmed)
- 15 g salt, plus more to taste
- 200 g white vinegar
- 100 g sugar
- 15 g mustard powder (dry mustard)
- 15 g mustard seeds
- 3 g ground turmeric
Instructions
- Add the trimmed cucumber, bell pepper and onion to a food processor and pulse to a fine dice. Transfer the chopped vegetables to a large colander over the sink, sprinkle with salt, stir to combine and let drain for at least 30 minutes.
- Meanwhile, combine the vinegar, sugar, mustard powder, mustard seeds and turmeric in a pot. Bring to a boil, then simmer 5–10 minutes to soften the mustard seeds.
- Sterilize jars by pouring boiling water into them and letting them sit for a few minutes, or run them through a hot dishwasher cycle.
- Add the drained vegetables to the pot, bring to a boil and cook 5–10 minutes until the mixture reaches your preferred consistency. Adjust seasoning as needed.
- Ladle the hot relish into prepared jars, leaving about 1 cm headroom. Seal immediately, let cool on the counter, then refrigerate.
Notes
- Be prepared for a lot of liquid to be released when you salt the chopped vegetables; drain over the sink or a bowl.
- Don’t over-process in the food processor — some texture is essential for a good relish.
- Turmeric and mustard powder can stain utensils and surfaces; avoid prized white or wooden tools if you want to keep them pristine.
Nutrition
Calories: 13kcal,
Carbohydrates: 2g,
Protein: 0.2g,
Fat: 0.2g
Nutrition information is automatically calculated and should be used as an approximation.
Like this? Rate and comment below!
