Pre-heat the oven to 180°C. Combine one tablespoon of the olive oil with the cubed pumpkin, place on a tray and roast in the oven until golden and tender. Remove and allow to cool.
To cook the quinoa - combine quinoa and two cups of water in a pot. Simmer, covered, for 15 minutes or until the liquid is absorbed and the germ turns opaque and splits from the seed - it should resemble little curls.
Boil the cleaned corn cob in salted water for 8 minutes. Remove, dry and grill over a flame for several minutes to lightly char the kernels. Remove them with a knife and set aside.
Combine the vinegar and remaining olive oil, season well and stir in all the remaining ingredients and serve.