Herring and Pumpkin Pie (Kiki's Delivery Service) / ニシンとかぼちゃのパイ (魔女の宅急便)

Name: Herring and Pumpkin Pie (Kiki's Delivery Service) / ニシンとかぼちゃのパイ (魔女の宅急便)
Prep time: 45 min
Cook time: 30 min
Total time: 1 h 15 min
Cuisine: Japanese
Ingredients: 1/2 kabocha ((approx 3/4 lbs)); 1/2 onion (diced); 1 tbsp olive oil; 1 can herring; 1-2 puff pastry sheets (frozen or homemade); black olives (cut); salt & pepper; shredded white cheese (can buy pre-shredded or grate yourself. can use any white cheese like parmesan, swiss, etc.); 2 tbsp butter; 2 tbsp flour; 1 1/4 cup hot milk; salt & pepper; 1 egg yolk; 1 tbsp milk