Heat oven to 350 degrees. Spread walnuts on a baking sheet and toast until fragrant and golden, about 7 minutes. Transfer to a bowl and cool Finely chop.
Melt 4 tablespoons butter in a large skillet over medium heat. Add mushrooms, scalliions, and thyme. Cook, stirring occasionally, until liquid is almost gone. Stir in Madeira, add 1 1/2 teaspoons salt and 1 teaspoon pepper. Cook about 10 minutes more. Let cool.
In a large bowl, mix mushroom mixture with parsley, lemon juice, hot red pepper sauce, cream cheese, and reserved walnuts. Season with salt and pepper. Refrigerate at least 8 hours. Serve with toast points or crackers. Serves 6 to 8.