Rinse and trim discolored ends from 2 pounds crimini, oyster, or common mushrooms (or a mixture) and coarsely chop.
In a 6-quart pan over high heat, melt 1/2 cup (1/4 lb.) butter. Add mushrooms, 1 cup chopped shallots, 4 peeled and minced cloves garlic, and 1 1/2 teaspoons each ground cumin and ground coriander. Cook, stirring often, until liquid has evaporated and mixture is lightly browned, 20 to 30 minutes.
In a food processor, whirl mushroom mixture until smooth. Mix in salt and pepper to taste. Mound in a bowl. Sprinkle with chopped parsley.