"Create a simple Southern egg custard pie recipe for a household of 4. Use metric units only. Keep it simple and suitable for average home cooking skills. Include common ingredients, clear steps, and make it work well with an air fryer if possible for finishing or reheating. Do not include turkey or kale. Avoid shellfish. Make it family-friendly, cost-conscious, and classic Southern-style with a smooth custard filling and simple pie crust. Use eggs, milk, sugar, vanilla, and nutmeg."