Bring a medium pot of salty water to the boil and cook the corn for 3 minutes. Remove and run under cold water to stop the cooking and allow to cool completely. This can be made in advance.
Cut the ripe tomatoes and set aside.
Roughly chop the basil, and finely chop the mint and chives.
Slice the feta into thin slices or cubes.
When you are ready to serve the salad, cut the corn from the cob in four strips around each side over a tea towel draped over a bowl. This will help catch any flyaway kernels. Empty this into the bowl.
Add the tomatoes, chopped herbs, olive oil and lime juice. Season well with sea salt flakes and freshly cracked black pepper to taste. Adjust the seasoning as you go. Bear in mind that feta is quite salty.
Add the sliced feta and toss lightly to combine.
Spread the salad out on a serving plate or platter and serve immediately.