Cook potatoes in a saucepan of boiling water for 10 minutes or until tender. Drain well and mash. Stir in cheeses, egg yolk and season to taste.
Meanwhile, heat oil in a large frypan over high heat. Cook mince for 5 minutes or until browned. Remove from heat, stir in Leggo’s Pasta Bake.
Spread mince mixture over the base of a round 22cm square baking dish. Top with mashed potato and bake in a preheated oven at 190ºC for 20-25 minutes or until golden. Stand for 5 minutes before serving.