Bake potatoes for 45 minutes in 400 degree oven until tender. Scoop out inside of potatoes, leaving 1/4 inch of potato in skin. Set aside. In skillet, saute onion and garlic until transparent, in about 2 tablespoons butter, add mushrooms, saute 3-5 minutes. Meanwhile chop lobster meat into bite-size pieces. Add to saute mixture, saute about 3 minutes, until it's heated through, turn burner to medium high, add the vermouth, cook until vermouth boils down. Set aside. Meanwhile, add sour cream to potatoes and hand mash together, add the cheddar and Gruyere cheese, mix together, add plenty of fresh-ground pepper, add beaten egg, add the lobster mixture, blend together, add scallions and 1/4 cup of Parmesan. Stuff potatoes with mixture, sprinkle with remaining Parmesan cheese. Bake in 350 degree oven until golden brown, about 15 minutes.