Preheat the oven to 450° F. Wash the potatoes and poke them all over with a fork. Line a baking sheet with foil or parchment paper. Put the potatoes on the baking sheet and bake for 25 minutes. Brush the outside of the potatoes with melted butter and sprinkle with salt. Return your potatoes to the oven and bake for another 20-25 minutes.
Check for doneness with a fork and, if not, cook for 5-10 more minutes. In the meantime, heat the Portobello Mushroom Sauce according to package instructions.
Remove the potatoes from the oven, slice them open lengthwise with a knife, and give them a good squeeze to open them up. Fluff them up with a fork, add your Portobello Mushroom Sauce, sprinkle with chives and serve.