Bring a large pan of water to the boil and cook the potatoes for 4 mins and remove. Cook the carrots for 4 mins and remove. Cook the the peas and mange tout for 1 min and finally the onions for 8-10 mins.
Slice the lamb fillets into good sized chunks and season with salt and freshly ground pepper. Heat 2tbsp of oil in a large pan and fry the lamb pieces for 6 mins on turning to brown all sides and cook through. Place the lamb on a plate and keep warm, reserve any juices that flow from the meat.
Place the pan back on the heat, add the wine and meat juices and reduce to a syrupy consistency. Add 200ml of the chicken stock and reduce by half then whisk in the butter and season with salt and pepper to taste, then stir in the chopped tarragon. Pour the sauce into a small bowl and wipe the pan.
Heat another tablespoon of oil and add the potatoes and onions until they start to brown, then add the sugar and a pinch of salt. Cook until the vegetables are caramelised. Add the ccarrots and balsamic, simmer and coast the carrots until they start to caramelise then add the stock. Bring to the boil and add the peas and mange tout and simmer until pan is almost dry.
To serve, place a few pieces of lamb in a bowl, add the vegetables and the stock and garnish with some chopped tarragon and a drizzle of the remaining olive oil.
Freezing and defrosting guidelines
Cook as instructed and allow to cool completely. Then transfer to an airtight, freezer-safe container, seal and freeze for up to 1-3 months. To serve, defrost thoroughly in the fridge overnight before reheating. To reheat and serve, place on medium heat, stirring occasionally until the dish is heated through.
For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.