bring a large pot of lightly salted water ot a boil. Add bowties, and cook until soft, about 7 minutes. Remove from heat, drain, and set aside.
At the same time, melt butter in a large heavy skillet over medium hear. Add onion, and cook, stirring until softened. Turn the heat up to medium-high, and add sliced mushrooms. Cook until the mushrroms are limp and browned. Remove to a bowl, and se aside
in the same skillet, stir in vegetable broth, being sure to stir in any browned bits of the bottom of the pan. Bring to a boil, and cook until the mixture has reduced by 1/3. Reduce heat to low, and return the mushrooms and onion to the skillet.
Remove the pan from the heat, stir together the sour cream and flour; then blend into the mushrooms. Return the skillet to the burner, and continue cooking over low heat, just until the sauce thickens. Stir in the parsley and season to taste with salt and peper. Serve over cooked bowties.
