In a small bowl, whisk together all the ingredients for the vinaigrette and set aside.
Remove the charred corn kernels from the cobs by placing the cobs on a clean work surface and shaving off all sides (a great trick is propping the corn into a bowl or a bundt pan, so you don't lose any kernals!) using a serrated knife. Place them in a large bowl.
Thinly slice the jicama and cucumber (preferably on a mandoline) and julienne them.
Into the bowl of corn kernels, add the jicama, cucumber, and dill. Toss gently with half of the vinaigrette until thoroughly combined. Finish by adding in the avocado cubes. Serve garnished with dill sprigs and with extra dressing on the side.
