Melt 2 tablespoons butter in a heavy skillet over medium heat. Add mushrooms and sauté until tender and browned and all juices have evaporated -- about 15 minutes. Remove from heat and set aside.
Melt 4 tablespoons of butter in another heavy large skillet over medium high heat. Add green onions. Sauté 2 minutes. Add chicken livers, salt and pepper and stir to coat. Cover and cook until no longer pink in the center, stirring often. About 10 minutes.
Remove cover and add sherry. Cook until sherry is almost evaporated -- about 2 minutes. Add wine, dry mustard, nutmeg, ground cloves and simmer uncovered for 1 minute. Using a slotted spoon, transfer the livers to a food processor. Puree about 30 seconds. Add wine mixture from skillet and process until smooth. Add cream cheese, remaining butter (1/2 cup) and all but 1/3 cup of the mushrooms. Puree until very well blended. Transfer pate to a serving dish, arrange the reserved mushrooms on top and cover with plastic wrap. Refrigerate at least 1 day or up to 2 days. Serve with sliced pears or apples, cornichons and gluten free crackers.
For an alternate presentation, line a loaf pan with plastic wrap overhanging on all sides and add the pate. Cover completely and refrigerate for 1 -2 days. Turn pate out onto a plate, remove cling wrap and slice pate into even slices. Top with reserved mushrooms.