Quick to make, this summer tomato salad with red onions, pickled in balsamic, is the perfect side dish to everything. Great with grilled vegetables and cheese, it highlights tomatoes in a whole new way.

sliced tomato salad served on a platt with red onions and basil scattered on the top

Every summer I fight a battle of what tomato thing to make first. Naturally I want to make all the things and I find a way to add tomatoes to dinner on a daily basis.  Tomato toast is by far my favorite thing to have for lunch and this summer tomato salad with balsamic red onion is  what I usually have for dinner. Because it goes with everything! 

Winter tomatoes are a mushy watery tasteless mess most of the time, I see no point in buying them then.  So summer is my tomato season. And we have so many options. Juicy, big, meaty heirloom tomatoes. Little plump cherry tomatoes and sweet datterinis. Plum tomatoes and all the other colorful varieties.  If someone opened a tomato restaurant I’d be the first in line. 

I make this tomato salad the same way my mom always made it, with a few upgrades like using white balsamic instead of red wine vinegar and basil to top it off. 

sliced tomatoes with basil and onion served on a plate

Notes on ingredients


Pick ripe tomatoes that are firm to the touch. If a tomato is too ripe and soft it can be mushy and we don’t want that. 

I like a variety of tomatoes, even though a single style would work just as well. Heirloom tomatoes are my favorite because they’re so meaty. I like to throw in some smaller sweeter cherry tomatoes to add more depth, a new range of flavor. And also the whole salad looks a lot better if you have some variety in shape and color. 

Here’s a short article on some tomato varieties.


This recipe focuses on white balsamic vinegar, but I actually have two favorites. White balsamic vinegar and red wine vinegar. I use both, interchangeably, depending on what I have on hand. 

White balsamic is made from both white wine vinegar and uncooked grape must. I like this vinegar because it has a more delicate, slightly fruity flavor and a light color so it doesn’t dirty-up the salad (like your regular balsamic would). This tomato salad has very few ingredients so using a good vinegar makes all the difference. 

Red wine vinegar is a great pick too. Firstly, it’s cheaper. It cuts deeper than balsamic, but I don’t find it too strong. Especially once it’s mixed with all the tomato juices. Its color is purple-ish red, but it mixes well into the dish so it won’t ruin your tomatoes. If anything it accentuates the color of the tomatoes and the onions. 

close view of sliced tomato salad with red onions and basil


Oh yes, this is a tomato onion salad. Onions add some much needed crunch to this salad. And also some sharpness. Tomatoes are sweet  and acidic. Onions balance that out and make this salad a lot more interesting. 

Red onions are my favorite pick for this. They’re sharp but almost a bit sweet and they look so pretty when sliced. The key here is slicing these as thinly as possible. 

You then put your thinly sliced onions in a vinegar bath and let them soak as you slice the tomatoes. I call this a quick pickle. We’re not really pickling onions here, but those 10 minutes are just enough to soften them a bit. 

If you can’t find red onions, use shallots. Shallots are milder than red onions but still offer more flavor than a classic white or yellow onion. 

green olives sprinkled with salt and basil on a plate with white wine in a glass on the side
Summer tomato salad with balsamic red onion, basil and olives on the side

Finishing touches 

  • Salt 

I’m using two types of salt. No need to worry that the salad is salty, it’s not. I like to use fine sea salt to season the vinegar. This is what gets poured all over the tomatoes. 

And then I like sea salt flakes to finish off the dish. The vinegar will pool underneath all the tomatoes, so adding a little something on top is my way of making sure every tomato tastes good. Sea salt flakes scattered around on top also make this salad look really inviting. 

  • Olive oil

I always keep extra virgin olive oil on hand and it shines in dishes like this tomato salad. I use it as a finishing oil and it just brings all of the flavors together. Juicy tomatoes on one side, vinegary onions on the other. Paired with olive oil, you have the most incredible vinaigrette and it took no effort at all. 

  • Basil

Theres nothing quite like the sight of tomatoes and basil together. This tomato salad is made with few ingredients, all fresh and beautiful and freshly picked basil on top just cements that. It makes the salad look super inviting and delicious. 

No basil? Sprinkle dried oregano all over. A bit different but I love it just the same.

sliced tomato salad leftover on a plate with bread

Serving suggestions

  • Roasted vegetables 

Oven roasted vegetables or vegetables cooked on the grill are the perfect companion for tomato salad. zucchini, eggplants, corn on the cob, potatoes and peppers are my favorite picks. 

  • Fresh bread and focaccia

Fresh soft bread and tomatoes make an incredible pairing. You can toast it if you wish as that works beautifully too. 

focaccia is an upgrade from that. Just imagine an olive rosemary focaccia and this salad together. Incredible! 

Summer tomato salad with balsamic red onion and basil
  • Cheese, all the cheese 

Cheese is a natural pairing for tomatoes. You can build a cheeseboard to serve with this tomato salad. Another option would be halloumi, especially if you’re making roasted or grilled vegetables too. 

  • Olives and other food to nibble on 

Almond stuffed olives are my favorite snack and I always eat them with this salad too. If you plan on making a cheese plate then olives and other nuts, crackers, pickled things (like stuffed peppers) would be great. 

  • Put it in a sandwich or burger

Yes! Juicy onion tomatoes are incredible in a sandwich. They act as both a juicy filling and a sauce and add so much flavor you hardly need anything else. 

Summer tomato salad with balsamic red onion

More summer recipes to explore

balsamic tomato salad with red onion


Summer tomato salad with balsamic red onion

Quick to make and very flavorful. Perfect pairing for cheese, grilled vegetables or as a burger topping. 
Prep 10 minutes
Total Time 10 minutes
Servings 2


  • 3 tablespoons white balsamic vinegar
  • 1/2 teaspoon fine sea salt
  • 1 small red onion thinly sliced
  • 2 large heirloom tomatoes
  • a handful of cherry and plum tomatoes
  • 2 tablespoons olive oil
  • a small handful of fresh basil
  • sea salt flakes


  • Whisk vinegar and salt in a medium bowl. Add onion and toss to combine. Let stand while you prepare tomatoes. Slice the heirloom tomatoes into disks. Slice cherry and plum tomatoes into wedges. 
  • Take a large serving plate or a shallow bowl and arrange the heirloom tomatoes on the bottom, they can overlap a bit. Top with 1/2 of the the onion-vinegar mix. Add tomato wedges, then top with the rest of onions and vinegar.
  • Drizzle with olive oil, sprinkle with salt flakes and basil leaves. Serve immediately.


You can store leftover salad in the refrigerator and eat within 1 day. It won’t look as pretty anymore but it will still taste good enough, especially if you eat it with roasted vegetables or in a sandwich. 
You can use red wine vinegar in place of white balsamic. And shallots in place of red onions. 

Join the discussion

Your email address will not be published. Required fields are marked *

Your Rating

This site uses Akismet to reduce spam. Learn how your comment data is processed.

  1. Meg @ Noming thru Life says:

    Now this is my kind of salad! Easy, fresh and has summer written alllll over it. And I love how you mentioned using it on burgers – great idea!

    1. Alice says:

      Glad you like it, Meg!

  2. Matthew Fisher says:

    5 stars
    I make this salad a load of times and I add olives and Feta to the salad before adding balsamic drizzle

    1. Alice says:

      Ooooh, I LOVE that combo! 🙂