the skills for cottage pie are generally classed as high(if there are no ready made ingredients) so you don't need to worry if your other dishes are high skill.Idk what exam board ur doing so I put both below
This is the WJEC dish 'stats':
Meat sauce:Knife skills – neat and small dicing of vegetables, crushing garlic, Sautéing, simmering
Potato topping:Knife skills – peeling and dicing potatoes, Simmering, Mashing – achieving a lump free and well seasoned mash,Piping potato,Even baking – good finished colour and good ratio of meat and potato layers
and this is the AQA 'stats':ComplexCottage pie: preparing fresh potato, filling, piping, gratin topping.