1. Put potatoes into a big pot of salted water and bring to a boil. Cook approximately 15 minutes or until fork-tender.
2. Scoop potatoes out into a bowl filled with ice water (to stop the cooking).
3. Cook the corn in the same boiling water for about 5 minutes.
4. Remove cooled potatoes to a cutting board and cut into quarters. Put in a large salad bowl.
5. Add corn to the bowl of ice water, until cooled. Drain.
6. Cut the kernels off of each ear of corn and add to the salad bowl.
7. Add the tomatoes, onion and whole basil leaves (you can tear or julienne them, if you want).
8. Add olive oil and lemon juice and toss gently to combine.
9. Season with salt and pepper.
10. Serve immediately or you can let the flavors meld.