There is something wonderfully refreshing about a bowl of crunchy cucumbers, ripe tomatoes and thin red onion slices glistening in a tangy dressing. Every bite is cool, juicy and bright, with a little snap from the cucumber and a gentle sweetness from the tomatoes.
This salad is the one to make when the garden is overflowing, when the oven is too hot to turn on, or when you need a quick side for a cookout, picnic or weeknight dinner. It comes together in about 15 minutes, and a short rest in the fridge lets the flavors mingle into something even better.
SaveMy mom used to make a version of this every July, piling the bowl high and setting it in the middle of the table next to the grilled chicken. Somehow it always disappeared first, and I still make it the same simple way whenever I want a little taste of summer.
Cucumber Tomato Onion Salad
Ingredients
Salad
Dressing
Instructions
- Prep the cucumbers
Wash the cucumbers well and trim off the ends. English cucumbers have thin skin and few seeds, so you can leave the peel on for color and crunch. Slice them into 1/4 inch rounds, then cut the rounds in half to make half moons and place them in a large mixing bowl.
- Slice the onion
Peel the red onion, cut it in half from root to tip, and slice each half as thinly as you can into half-moon strips. Thin slices keep the onion tender rather than harsh. Add them to the bowl with the cucumbers.
- Mellow the onion
If your onion is strong, place the slices in a small bowl of ice water for 5 minutes, then drain and pat dry with a paper towel. This quick soak takes away the sharp bite while keeping the onion crisp and pretty.
- Cut the tomatoes
Core the tomatoes and cut them into bite-size wedges, about 8 per medium tomato. Use a sharp knife and a gentle sawing motion so the tomatoes keep their shape and do not get squashed. Set them aside in a separate bowl for now so they stay firm.
- Whisk the dressing
In a small bowl or a jar with a lid, combine the olive oil, red wine vinegar, sugar, minced garlic, kosher salt, black pepper and dried oregano. Whisk or shake for about 30 seconds until the dressing looks glossy and the sugar and salt have dissolved.
- Marinate the cucumbers and onion
Pour about two thirds of the dressing over the cucumbers and onion and toss well to coat every slice. Let the bowl sit on the counter for 10 minutes so the vegetables soak up the tangy flavor.
- Add the tomatoes
Gently fold the tomato wedges into the bowl, along with the chopped parsley or basil. Fold with a large spoon rather than stirring hard, so the tomatoes stay intact and do not release too much juice.
- Taste and adjust
Taste a cucumber slice and a piece of tomato together. Add a pinch more salt if the flavors seem flat, a splash of vinegar if you want more tang, or a drizzle of the remaining dressing if the salad looks a little dry.
- Chill briefly
Cover the bowl and refrigerate for 20 to 30 minutes. This short rest lets the salt draw out some juices that blend with the dressing, creating a light, flavorful sauce at the bottom of the bowl.
- Toss and serve
Give the salad a final gentle toss just before serving, then spoon it into a serving bowl with a slotted spoon or serve it in its juices for mopping up with crusty bread. Garnish with a few extra herb leaves and a crack of black pepper.
Substitutions and variations
- Swap the red wine vinegar for apple cider vinegar or fresh lemon juice if that is what you have in the pantry.
- Use cherry or grape tomatoes, halved, in place of the larger tomatoes for a sweeter, neater salad.
- Add 1/2 cup crumbled feta and a handful of Kalamata olives for a Greek-inspired version.
- Replace the red onion with thinly sliced green onions or shallots if you prefer a milder bite.
Chloe's tips
- Choose firm, ripe tomatoes that smell fragrant at the stem end, since they are the star of this simple salad.
- Keep the tomatoes out of the bowl until the last few minutes of marinating so they stay firm and do not turn watery.
- A mandoline makes quick work of paper-thin onion and evenly sliced cucumbers, just use the guard.
- If you are making this ahead, hold back the tomatoes and herbs and add them just before serving for the best texture.
How to store it
- Store leftovers in an airtight container in the refrigerator for up to 2 days, though the cucumbers are crispest within the first 24 hours.
- Drain off excess liquid before serving leftovers and refresh with a small splash of vinegar and a pinch of salt.
- This salad does not freeze well because the cucumbers and tomatoes turn mushy once thawed.
Serving suggestions
This cool, tangy salad pairs beautifully with just about anything hot off the grill.
- Alongside grilled chicken, burgers or barbecue ribs at a summer cookout
- Spooned over warm pita with hummus for an easy lunch
- Piled on top of grilled fish or shrimp as a fresh topping
- Served with a sandwich or wrap in place of chips
- Tossed with cooked chickpeas and feta for a light main dish
Frequently asked questions
Can I make cucumber tomato onion salad ahead of time?
Yes. You can slice the cucumbers and onion and mix the dressing up to a day ahead, keeping them separate in the fridge. Add the tomatoes and herbs and toss everything together about 30 minutes before serving for the freshest texture.
How do I keep the salad from getting watery?
Salt draws moisture out of cucumbers and tomatoes, so add the tomatoes late and serve within a few hours. You can also scoop the salad out with a slotted spoon to leave the extra liquid behind.
Should I peel the cucumbers?
It is not necessary with English or Persian cucumbers because their skin is thin and tender. If you use regular garden cucumbers with thick or waxy skin, peel them and scoop out the seeds with a spoon first.
What kind of onion works best?
Red onion gives the best color and a mild sweetness when sliced thin. Sweet onions such as Vidalia also work well if you want a gentler flavor.
Let's get cooking!
Simple, bright and endlessly flexible, this cucumber tomato onion salad proves that a few fresh vegetables and a good dressing are all you need for a memorable side. Make a big bowl, set it on the table and enjoy every cool, crunchy bite.
