How to make cheese and onion pie

Laziest Cheese and Onion Pie you’ll ever make. Ingredients: - 2 tbsp Veg Oil - 1 large or 2 medium white onions - Knob of Butter - Frozen mash 500-700 - Splash of milk - Handful of Red Leicester Cheese - Handful of Mozzarella Cheese *you can use 2-3 handfuls of grated four cheese mix if you wish (instead of Red Leicester and mozzarella), this gives more flavour. - Mozzarella to go on top - 2 Shortcrust or puff pastry - 1 egg Method: 1. Heat the oil in a pan, then add diced onion. Add in a pinch