Cook your pasta according to the directions on package. Save ½ cup of the hot pasta water and dissolve the teaspoon of beef bouillon in it and set aside.
Heat up a large skillet on medium heat and add the 2 tablespoons of butter and let melt. Add your sliced mushrooms to the pan. (If your pan is over crowded you may do this in 2 batches, just use a bit more butter.) Cook until golden.
Remove the mushrooms after they are cooked, keeping the heat on medium add the whipping cream, rosemary, vanilla garlic, soy sauce and the pasta water with beef bouillon. Simmer 10 minutes to heat through and reduce.
After 10 minutes re-add the mushrooms. Let them warm through and add your pinch of nutmeg, ½ cup of Parmesan cheese and season with ground black pepper to taste.
Toss in pasta gently and mix it all together. Serve warm.