In a skillet over medium, saute the 1 medium onion in 1/2 cup butter for 4-5 minutes. Add the 1 pound cremini mushrooms and garlic and cook for 5 minutes. Add 1/3 cup dry sherry, 1 teaspoon salt and 1/4 teaspoon black pepper and cook for 10 minutes. Set aside and let cool slightly.
Preheat oven to 350 degrees.
Combine 8-oz. package cream cheese, 3 eggs, 2 cups spinach, 1 1/4 cups walnuts, and 1 Tablespoon tarragon , then add in cooled mushroom mixture.
Place mixture in a buttered loaf pan. Cover with aluminum foil. Place loaf pan in larger and deeper pan partially filled with water. Bake for 1 hour 15 minutes.
After baking, remove from oven and chill inverted on a plate. Once chilled, the pate may be sliced and served.
Notes
Storage
This vegetarian pate will keep in the fridge (tightly wrapped) for up to 5-days.
You can also freeze this vegetarian pate for up to 3 months. Wrap it tightly with plastic wrap, then a layer of tin foil.