Preheat the oven to 180C. Wash the potatoes and prick several times with a fork. Bake for about 1 hour or until soft.
Once the potatoes are baked. Melt butter in a pan and saute the mushrooms for a couple of minutes. In the meantime cut the potatoes lengthwise, scoop out the soft part and add it in the pan with the mushrooms, then add the spinach and cheese and let it fry over low heat for a couple of minutes.
Spoon the filling back in the potatoes and place them back in the oven for another 10minutes.
Best served warm.
I like having them with fresh tomatoes and the white herby dip. (optional)