Break up the mince in a large, deep pot. Pour in water, and season with 1 teaspoon of salt. Cover and soak beef for about 20 minutes at room temperature. Add whole potatoes, carrots, parsnips and onions. Stir in additional water, if needed, until potatoes are mostly covered.
Cover the pot and bring to the boil slowly over medium-low heat. Reduce heat to low and simmer until the potatoes begin to fall apart, about 1 hour, adding water as needed, to keep the stew moist. Season with salt to taste. Cover, remove from heat, and allow stew to rest for 10 minutes before serving.