Place potatoes in a steamer and steam 40-45 minutes or until soft. Set aside and let cool. Once cooled slice in half and carefully scoop out the insides of the potato leaving the outsides walls sturdy and intact. Set aside potato pulp.
Preheat oven to 350F.
Remove stems from mushrooms and reserve for another use. Set aside caps.
In a bowl beat together cream cheese, blue cheese, pecans, green onion, basil, a pinch of salt and pepper and 2 tbsp potato pulp, until blended.
Stuff mushroom caps with cheese mixture, mounding slightly. Fit stuffed mushrooms carefully inside cooled potato halves. I even placed a small dab of the cream cheese filling on the inside bottom of the potato half to help the mushroom stick and stay in place. Place stuffed potatoes on a parchment lined baking pan and sprinkle with salt and pepper.
Bake in oven for 10 minutes or until cheese bubbles & browns a little. Sprinkle with parsley and even some cooked crumbled bacon. Serve immediately.
Do not freeze.