Directions
Heat oil in skillet over medium-high heat. Add onion and potatoes and sauté until translucent. Add thyme and mushrooms and sauté until mushrooms begin to brown. Add sherry and cook until liquid evaporates. Stir in the broth and bring to a boil and cook again until liquid is reduced by half and potatoes are tender. With a hand blender, or by placing gravy into an upright blender; blend until smooth. Return to pan and bring to a simmer. Season with salt and pepper to taste. Remove from heat; stir in butter 1 tablespoon at a time.