In a large bowl, whisk together 2 tablespoons extra virgin olive oil. 1 tablespoon apple cider vinegar, ½ teaspoon kosher salt, and ½ teaspoon freshly cracked black pepper until well combined.
Add the diced tomatoes, sliced cucumbers, and thinly sliced onions to the prepared dressing and gently toss gently to coat the vegetables with the dressing.
Cover and let rest for 30 minutes or up to 4 hours. If planning to enjoy within 30 minutes, you can leave at room temperature. Any longer, it is best to refrigerate.
Right before serving, add the basil, gently toss, and taste to see if any additional seasonings are needed. Then serve immediately.
Notes
Tomatoes: Use any variety of seasonal ripe tomatoes you like. Out of season, replace the vine-ripened tomatoes with 1 pint of halved grape or cherry tomatoes.English/Hothouse Cucumber: Feel free to use regular cucumber in place of an English cucumber. Just be sure to peel and remove the seeds for best results.No Apple Cider Vinegar? Replace it with fresh lemon juice, red wine vinegar, or white wine vinegar. Optional Spices: Feel free to add up to ½ teaspoon dried oregano or 1 teaspoon minced garlic, if desired. Note on Storage: This salad is best served within 4 hours after preparation. After that, the salad will begin to become watered down and soggy.