Tomato Onion Salad with Balsamic Vinegar is made with just a few simple, fresh ingredients. Loaded with seasonal summer flavors and crumbles of blue cheese, it’s as delicious as it is beautiful, and perfect for casual entertaining. 
The first time I was served a Tomato Onion Salad like this, I was on the Big Island of Hawaii.
The onions were almost as sweet as the tomatoes, and it was presented much like a Caprese salad, with the large slices of sweet onion in lieu of mozzarella.
Made almost entirely of fresh, seasonal garden ingredients, whether you make a large platter or individual servings on small plates, it’s sure to be a huge hit!
Ingredients for Tomato Onion Salad
- heirloom tomatoes
- sweet onions (i.e., Maui, Vidalias or Walla Wallas)
- fresh basil leaves
- blue cheese crumbles
- balsamic vinegar
- black pepper
- salt
How to Make it
– Thinly slice tomatoes and onions into large rounds.
– Alternating between them, arrange the tomato and onion slices on a round plate (or platter). Add a few basil leaves between the slices, and crumbles of blue cheese on top.
– Add the balsamic vinegar to a very small sauté pan and place it over medium-high heat. Cook until it thickens and reduces by about half.
– Drizzle the reduced balsamic over the tomatoes and onions and then sprinkle lightly with salt and pepper.
Recipe Tips and Substitutions
- The key to a salad like this (and most recipes, of course) is starting with the best ingredients possible. Especially since everything is raw — we want each flavor to shine on its own.
- During the summer, tomatoes and sweet onions are best from your local Farmers Market (here’s a directory to find one near you). And if you happen to have any of these things growing in your garden, even better!
- If you can’t find any of the sweet onions listed (Maui, Vidalia or Walla Wallas), use a red onion. They are typically on the sweet side year round.
- A variety of colors of tomatoes will make the presentation extra special, but it’s more important the tomatoes taste good — so get whichever colors are the most ripe and the most delicious.
- Vary the amounts if you want, depending on how many you’re serving. If you want to make a large centerpiece platter for example, just add more of everything. Simple!
- Thickening the balsamic vinegar makes it richer and sweeter. If you’re pressed for time, or don’t want it too sweet, just drizzle it on top as is.
Can you make it ahead?
Arrange the ingredients up to a couple hours ahead of time. Cover with plastic wrap and refrigerate until you’re ready to serve. (The balsamic glaze should not be added until the moment you serve.)
I hope you love this Tomato Onion Salad!
More delectable summer salads:
- Mango-Manchego Basil Salad
- Compressed Watermelon Salad
- Watermelon Basil Salad with Avocado
- Grilled Little Gem Lettuce Avocado Salad
- Tomato and Cucumber Salad with Lemon
- Peach and Avocado Salad with Zucchini
- Nicoise Salad Cups with Lemon Dressing
Tomato Onion Salad Recipe
Ingredients
- 2 tomatoes (about the size of plums) washed, dried, sliced into thin rounds
- 1 sweet onion (Maui, Vidalia or Walla Wallas)* peeled and sliced very thinly
- 10 large basil leaves, washed and dried
- 1 tablespoon crumbled blue cheese,
- 2 tablespoons balsamic vinegar
- salt and freshly ground black pepper
Instructions
- Arrange tomatoes and onions. Alternating between the tomato and onion slices, arrange them on a round plate. Add a basil leaf here and there between them, and then sprinkle the blue cheese over the top.
- Reduce the vinegar. Add the balsamic vinegar to a very small sauté pan and place it over medium-high heat. Cook until it thickens and reduces by about half.
- Assemble. Drizzle the reduced balsamic and grind a bit of the salt pepper over the tomatoes and onions and serve.
John / Kitchen Riffs says
Local tomatoes are just at the beginning of their season, so your timing is perfect. What a wonderful dish! Lovely starter, or I’d be tempted to serve a large portion of this as a main course. Thanks!
valentina says
Hi John. Our tomatoes are just reaching their prime too. I saw some beauties this morning at the Farmers’ Market. Enjoy and thanks! 🙂 ~Valentina
Eha says
This perfect plate needs the most careful homework at the Farmers’ Market – simplicity for which I shall have to wait till Christmas . . . .shall not forget . . . and my favourite Kangaroo island blue will be there waiting . . .
valentina says
Hi Eha. Thanks for visiting. I love spending time at the Farmers’ Market to find the perfect fresh and local ingredients. Enjoy at Christmas. 🙂 ~Valentina
Chef Mimi says
This is beautiful! I can’t wait till my garden really starts producing.
valentina says
Fun. I only have herbs (which I love), and wish I had the room to grow so many things. Enjoy and thank you, Mimi. 🙂 ~Valentina
Linger A Little, Kristy says
Oh my goodness! What a fresh and gorgeous salad for summertime. The onion is such an interesting addition that goes perfectly with the rest of the ingredients. And there’s no better cheese than blue cheese to sprinkle on top. Thanks for sharing.
valentina says
Hi Kristy. Thanks for checking this recipe out. I’m so with you on the blue cheese. 🙂 ~Valentina
David says
As beautiful as this is, there is no way I could eat the slices of raw onion! I’m just too old! 🤷🏼♂️ I can happily put together the rest of it…
valentina says
Ha! I slice them very thinly. 😉 Enjoy the rest. ~Valentina