Rinse the quinoa in a fine sieve. In a medium pot of boiling water, cook the quinoa for 12 minutes, or until the germ separates and there's the merest white dot left at the core. Drain through the sieve and return to the dry pan; remove from heat, cover with a tea towel and let steam for another 10 minutes or so. Transfer to a shallow bowl and set aside to cool.

Husk the corn while you preheat the barbecue to high. Place the cobs directly on the grill and cook, turning until charred all over, about 10 minutes. Let cool slightly, then cut the kernels off the cob into a wide bowl. Add the remaining ingredients and toss to combine.

To make the vinaigrette, shake all the ingredients up in a jar, then drizzle over the salad.