sausages and mashed potatoes (= boiled potatoes that have been made into a soft mass). The phrase is often used as an example of a simple, solid and very British meal
I'd rather eat bangers and mash than an expensive meal in a French restaurant.我宁愿在法国餐馆里吃香肠和土豆泥，也不愿吃一顿昂贵的饭。