Whisk all dressing ingredients together until fully emulsified. Taste and adjust until bright, tangy, and smoky. Set aside.
Heat a large skillet over the highest heat possible until smoking. Add corn kernels in a single layer with no oil.
Do not stir for 2 minutes. Let the corn char undisturbed. Toss and cook for 2 to 3 more minutes until golden and caramelized. Work in batches if needed.
Transfer charred corn to a large bowl and cool for 5 minutes.
Soak diced red onion in cold water for 5 minutes. Drain and pat dry.
Add cherry tomatoes, red onion, chili, cilantro, and parsley to the corn. Toss to combine.
Pour dressing over the salad and toss well to coat everything evenly. Taste and adjust seasoning.
Add diced avocado last and fold through gently with just two or three large movements.
Scatter feta or cotija cheese over the top if using. Finish with a final squeeze of fresh lime.
Serve immediately garnished with extra cilantro and lime wedges.