For this delicious pico de gallo, use the freshest, juiciest corn you can find because the kernels are not cooked. Slideshow: Great Grilled Fish Recipes
In a medium bowl, toss the corn with the cherry tomatoes, chile, cilantro and lime juice. Season the pico de gallo with salt.
Light a grill and brush the grates with olive oil. Season the fish with salt and grill over high heat, turning once, until charred on the outside and opaque throughout, about 4 minutes per side.
Meanwhile, grill the tortillas until warm and lightly charred, about 30 seconds per side. Top the tortillas with the fish, pico de gallo and diced avocado. Fold the tortilla over the filling and serve right away.