Toast almonds in a heavy ungreased skillet over low heat for about 5 minutes. Stir frequently. Remove almonds to a bowl and set aside.
Melt butter or margarine over low heat in the same skillet. Add onion and saute 5 minutes. Stir in mushrooms, garlic, salt, thyme and black pepper. Cook over low heat, stirring frequently, until liquid evaporates.
Reserve 2 tablespoons of the toasted almonds. Place remaining almonds in a blender with mushroom mixture. Add vegetable oil and process until pureed. Remove from blender to a bowl. Stir in reserved almonds.
Store in a covered container in the refrigerator.