Pierce the washed potatoes 10 times with a fork. Place evenly around outer edge of microwave turntable. Cook on High/100% power for 6 minutes. Turn the potatoes over and cook a further 5-6 minutes on High / 100% power or until firm when tested with a skewer (the skin should be unwrinkled and potatoes firm). Alternately pierce potatoes 10 times with a fork and bake for 1 hour in 200°C oven until tender. Wrap each potato in a piece foil and leave for 10 minutes.
Heat oil in a non-stick frying pan over medium heat. Add the onion and cook, stirring occasionally for 6 minutes or until onion is soft. Increase heat to medium-high, add the mushrooms. Cook for 5 minutes until mushrooms are tender. Stir in snipped chives and swirl through the yoghurt. Season to taste.
Cut a deep cross in the top of each potato. Using a clean tea towel to hold the potato, squeeze the base gently to open up the top then place onto a serving plate. Spoon over the mushroom mixture and serve.