Wash and pierce each potato. Wrap in foil and bake at 350º for about an hour, or until tip of knife pierces easily.
While the potatoes are baking, prepare the filling.
In skillet, melt butter and saute the onions and garlic until fragrant.
Quarter the mushrooms and add to the pan, saute until cooked (just a few minutes).
Salt & pepper the mix.
In a small saucepan steam the broccoli in about 1/2 cup of water and a little salt, until tender.
When potatoes are finished baking, de-foil them and place them in a cereal bowl, or other kind of shallow dish.
Split potato and fill with the broccoli, then pour the mushroom mixture over all.
Top with sour cream and grated pepper jack cheese.