15-Minute Tomato Cucumber and Onion Salad

Ingredients

• 450 g (1 lb)cherry tomatoes, halved
• 450 g (1 lb)slicing cucumber, halved lengthways, seeds scraped out and cut into chunky slices
• 90 g (1 cup)red onion, thinly sliced into half-moons
• 1–2 tbspfresh herbs, such as dill and/or basil, chopped or torn
• 45 ml (3 tbsp)extra virgin olive oil
• 30 ml (2 tbsp)red wine vinegar
• 2.5 ml (½ tsp)Dijon mustard
• 0.6 ml (⅛ tsp)fine sea salt
• A generous pinchfreshly ground black pepper

Instructions

1. 1

   Combine the vegetables

   Put the halved tomatoes, chunky cucumber pieces and sliced onion in a medium mixing bowl. Scatter the fresh herbs over the vegetables.

2. 2

   Mix the dressing

   Add the red wine vinegar, olive oil, Dijon mustard, salt and pepper to a lidded jar or small bowl. Shake or whisk until the dressing comes together as an emulsion.

3. 3

   Dress the salad

   Pour the dressing over the vegetables and toss gently. Taste and adjust the salt and pepper as needed.

4. 4

   Finish with herbs

   If you like, scatter extra herbs over the salad just before serving.

5. 5

   Chill for storage

   Keep the salad in a lidded container in the refrigerator for up to two days. By the third day, the vegetables start to become soggy.

What is tomato cucumber and onion salad?

This American-style summer salad brings together juicy tomatoes, crisp cucumber and sharp red onion in a simple vinegar-and-oil dressing. It is a fresh side dish made from familiar ingredients rather than a cooked recipe with a single fixed tradition.

The combination works because the vinegar and mustard give the sweet, watery vegetables a tangy contrast, while fresh herbs add fragrance. Making it a few hours ahead gives the dressing time to flavour the vegetables.

Nutrition and macros by portion

The nutrition label shows one serving as written: 145 calories, 2g protein, 11g carbs, 11g fat.

The tomatoes and cucumber contribute most of the carbohydrates, while the olive oil supplies most of the fat. The vegetables and herbs provide only a modest amount of protein, so pair a serving with a protein-rich main such as beans, fish or chicken to make a more balanced plate.

Choosing the vegetables

Cherry tomatoes: Halving them exposes their juicy centres so the dressing can coat them easily. Choose firm tomatoes that hold their shape when tossed.

Cucumber: Scraping out the seeds helps limit excess liquid, while chunky slices stay substantial in the bowl. A slicing cucumber is a good fit for this texture.

Red onion: Thin half-moons distribute the onion through the salad without overwhelming each mouthful. Slicing it evenly also helps it take on the dressing.

Making an emulsified dressing

Mustard: Dijon helps the oil and vinegar combine into a more cohesive dressing. Measure it carefully so it supports rather than dominates the fresh flavours.

Mixing: Shake the ingredients in a lidded jar or whisk them in a small bowl until the dressing looks blended. If it separates while the salad rests, give it another shake or stir before serving.

Getting the texture right

Keep the toss gentle so the tomatoes remain intact and the cucumber slices do not break apart. The finished salad should look lightly coated, not mashed or swimming in dressing.

Taste after tossing, when the dressing has reached all the vegetables. Add salt or pepper a little at a time, then toss again to distribute it.

Choosing and adding herbs

Dill: Its distinctive, fresh flavour suits cucumber particularly well. Chop it before adding so it spreads through the salad.

Basil: Tear the leaves rather than chopping them, as the recipe suggests, and add them close to serving for a fragrant finish. You can use either herb or a combination.

Making it ahead and serving

For the best flavour, prepare the salad a few hours in advance and keep it chilled. The vegetables soften as they sit, so avoid making it more than two days before serving.

Serve it alongside grilled vegetables, fish, chicken or a savoury tart for a light summer meal. It also works as a fresh contrast to richer dishes.

Recipe notes & tips

• Use a sharp knife to make even tomato halves and onion slices.
• Scrape the cucumber seeds out before cutting it into chunks.
• Shake the dressing again if it separates before you pour it over the salad.
• Start with 1 tablespoon of herbs, then add more to suit your taste.
• Add any extra herbs just before serving for a fresh aroma.
• Taste the dressed salad before serving and adjust the seasoning gradually.

Variations

• Use basil: Tear the leaves and add them just before serving for a fragrant version.
• Use dill: Chop it finely for a fresh, cucumber-friendly herb flavour.
• Mix the herbs: Combine dill and basil within the recipe's 1–2 tablespoon amount.
• Adjust the tang: Add the dressing gradually and stop when the salad is dressed to your liking.
• Add extra pepper: Grind more black pepper over the salad just before serving.

Common mistakes to avoid

• Leaving cucumber seeds in: Scrape them out first to help limit excess moisture.
• Cutting the onion too thickly: Slice it into thin half-moons so it spreads evenly through the salad.
• Overmixing: Toss gently to avoid crushing the tomatoes and cucumber.
• Skipping the taste check: Taste after dressing and adjust salt and pepper before serving.
• Storing it too long: Eat within two days, as the vegetables become soggy by the third day.

How to store

Store the salad in a lidded container in the refrigerator for up to two days. Its texture softens over time, so it is best eaten before the third day; this fresh salad is served cold rather than reheated.

Frequently asked questions