Method

• 1.
  Place potato in a saucepan of cold, salted water. Bring to the boil, then reduce heat to medium and cook for 5-10 minutes until par-cooked. Drain, cool and thinly slice.
• 2.
  Preheat oven to 190°C. Heat oil in a large fry pan over high heat. Season the lamb, then cook, turning, for 8-10 minutes until browned. Remove from pan and reduce heat to medium.
• 3.
  Add the onion and carrot, then cook, stirring, for 4-5 minutes until softened. Add the rosemary and cook for a further 1 minute or until fragrant. Add the stock and pasta sauce, scraping the bottom of the pan with a wooden spoon. Bring to a simmer, then season and cook for 3-4 minutes until slightly reduced.

• 4.
  Place lamb in a baking dish and pour over the tomato sauce. Layer potato over the top and season, then brush with oil. Bake for 1 hour or until potato is golden.
• 5.
  Rest for 5 minutes, then serve garnished with extra rosemary sprigs.