Heat a medium skillet over medium heat. When hot, add pine nuts and toast until lightly brown, shaking pan to prevent burning, 3 to 4 minutes. Remove from skillet and set aside. Add 1 tablespoon olive oil to pan; when hot, add mushrooms and cook until softened, 3 to 5 minutes. Add garlic and thyme and cook, stirring, until fragrant, 2 minutes. Add sherry and bring to a boil over high heat. Simmer until liquid has evaporated, 1 to 2 minutes. Remove from heat and allow to cool slightly. Place reserved pine nuts, mushroom mixture, cheese, and parsley in food processor; pulse until well chopped. With machine running, slowly add 3 tablespoons olive oil in a steady stream, allowing pesto to mix blend and become cohesive. Process until desired consistency is reached, season with salt and pepper, and serve over warm penne noodles.