Whisk together all the dressing ingredients in a small bowl. Taste and add more salt or pepper if needed. Set aside.
Heat up a large skillet over medium heat. Once nice and hot, add the olive oil and place the zucchini cut-side down. Cook for 5-7 minutes or until golden brown. Remove from the skillet and place on a plate. Lightly sprinkle with salt and set aside. Repeat with remaining zucchini.
Add the corn kernels to the skillet, season with ½ teaspoon of kosher salt and ¼ teaspoon of black pepper. Cook for 6-8 minutes, stirring occasionally.
Cut zucchini into half-inch pieces and cut each piece in half again. Add to a large bowl along with the corn and toss with the dressing to combine. Serve with feta and chopped fresh basil.