Marinated Cucumber, Tomato, And Onion Salad

The flavors of the dressing in this cucumber, tomato, and onion salad pull the natural juices out of the vegetables, which then get re-absorbed into them for a punchy, juicy salad that is at once refreshing and comforting.

The cucumbers and onions take on an almost pickled texture, while the tomatoes get slightly slumpy—a great way to either celebrate the ripest of heirloom garden tomatoes, or to salvage some less-than-perfect grocery store varieties. And since you make it a day ahead, it's the ideal pre-prepped dish for your next backyard gathering or potluck offering.

But one of my favorite things about it is that it is endlessly adaptable for whatever style of salad tickles your fancy. This versatile salad can be eaten as-is, piled on top of lettuce or greens, or forked through cooked pasta or rice. Add crushed crunchy pita chips for a riff on Fattoush or toasted torn pieces of sourdough for a version of a panzanella.

Learn how to make cucumber, tomato, and onion salad. Any leftovers can be whizzed up in your blender for an instant gazpacho.

Ingredients in a Cucumber, Tomato, and Onion Salad

When you're making a simple salad like this cucumber, tomato, and onion salad, it's imperative the ingredients you use are as fresh and bright as possible. Why? When so few ingredients are used, you taste every single one of them. So while this salad is quite humble in its ingredient list, focus on quality, and the results will be stellar.

• Heirloom tomatoes: Preferably beefsteaks. The meatier the tomato, the better it will absorb and stand up to the marinade. But heirloom beefsteaks are pricier, so if you're looking to not drop a few bucks on each tomato, just go for the highest quality tomato you can afford. If you're craving this salad out of tomato season, reach for Romas or cherry tomatoes instead. Slice or chop them up a bit more so the flavors of the marinade can really soak in.
• English cucumbers: English cucumbers are the preference for this salad because they often have thinner skins and are slightly sweeter than Kirbys. Though this recipe calls for peeling the cucumbers, you don't have to—in which case, the English cucumbers really will be preferred.
• Red onions: You might think we'd call for Vidalia onions in this cucumber salad, but we're steering toward the reds here because they are spicier and can stand up to the long soak in the marinade. Sweeter onions, like Vidalia or yellow onions, have enough bite that they could be used, but because they're already a bit mellow, you may lose some zip after they've marinated.
• Vinegar: Sherry vinegar or red wine vinegar, both of which have a slightly sweet edge to the vinegar bite. But you can actually use any vinegar you like or have. Even plain white distilled vinegar would work, but you may want to amp up the sweetness a bit by adding a pinch of sugar to the dressing.
• Herbs: There are herbs in the dressing and herbs as a garnish. We like herbs de Provence, a blend of thyme, tarragon, basil, rosemary, oregano, and a few others, because it's a rich and warming mix. But it can be expensive and difficult to find, so a traditional Italian herb mix can work, too.

How To Make Cucumber, Tomato, and Onion Salad

The process of making cucumber, tomato, and onion salad is incredibly simple. With all the chopping and mixing, everything is done in about 10 minutes, 15 if you double the recipe for a big crowd. But you have to wait 12 to 24 hours before this salad is ready to eat. And that's the hard part.

• Step 1. Make the dressing: In a small bowl, combine the olive oil, vinegar, dried herbs, salt, and black pepper. Crushed red pepper flakes are optional. They infuse a hint of heat in this, which is elevated by the vinegar-based dressing. Not sure which you'd like better? Split the dressing and the vegetables to make one with the pepper and one without. Sensitive palates and kid eaters will appreciate the option.
• Step 2. Add the vegetables: Pour the dressing over the bowl of prepared cucumbers, tomatoes, and onions. Gently toss to coat. Leave the bowl sitting on the counter for 1 hour. This gives the marinade time to soften the vegetables and begin to pull out some of their natural juices. After an hour, give the cucumber, tomato, and onion salad a quick stir, then cover the bowl with plastic wrap or a lid and slide into your fridge.
• Step 3. Marinate: Let the salad sit overnight in the fridge, or up to 24 hours. Every few hours, stir the salad a bit to recoat the vegetables with the dressing. This will help infuse the tomatoes, cucumbers, and onions with the flavorful dressing.
• Step 4. Bring to room temp before serving: Before you serve this salad, bring it out of the fridge, and let it sit at room temperature for 30 minutes to an hour. In this time, the vegetables will warm slightly, helping release the natural juices that are now beautifully mingled with the dressing. Give the salad a few turns with a spoon, and top with any fresh herbs of your choosing.

How To Store Cucumber, Tomato, and Onion Salad

Cucumber, tomato, and onion salad can be stored in the fridge. After the initial 12 to 24 hours marinade, you can keep it in the cooler for up to another four days. However, keep in mind that the vegetables will continue to soften as they sit, so by the end, they may be quite tender.

No worries, though! Give the vegetables and a spoonful or two of the marinade a quick buzz in a food processor, and you've got a fresh summer salsa. Keep going, with a bit more leftover juice, and you've got gazpacho. Or finish up the vegetables, and take the marinade for use as a fresh and effortless salad dressing. This is the summer gift that keeps on going.

More Cucumber Salads

Cucumber salads are the greatest side for spring and summer when you crave something fresh and easy. There are a few of our favorites:

• Creamy Cucumber Salad
• Smashed-Cucumber Salad
• Cucumber And Vidalia Onion Salad
• Cucumber-Tomato-Avocado Salad
• Watermelon, Cucumber, and Feta Salad
  

Editorial contributions by Kimberly Holland.