Heat butter or oil in a heavy skillet over high heat. Add a teaspoon of smoked paprika and oregano.
Add the corn and let it sit undisturbed for 2-3 minutes to get a deep, golden char. Toss and cook for another 3 minutes, then remove from heat to cool completely.
Soak cashews in boiling water for 15 minutes. Drain them, and blend them with salt, garlic, and peppercorns until coarse.
Add sour cream, herbs, lime juice, and blend till it is smooth and creamy with a spoon dropping consistency.
Combine the cooled corn, finely diced red pepper, red onion, and cucumber. Pour the dressing over the top and toss to coat uniformly. Top with crumbled Cotija or feta cheese, and let it chill in the fridge for at least 30 minutes before serving.