Preheat the Dutch oven with a splash of oil, then add the diced lamb.
When the lamb is browned on the outside add the diced onion. Cook the lamb until transparent and starting to brown. Add the red wine to deglaze, then add water until the meat is covered.
Add the sliced carrots and peas to the lamb mixture. Place the lid on the Dutch oven and leave to simmer.
Cheesy Mashed Potatoes
In a heat-proof bowl add the instant potatoes and grated cheddar cheese.
Add boiling water directly onto the cheese. Stir together the instant potatoes, cheese, and hot water until smooth. If desired bring it to a creamy consistency by adding a dash of cream.
To Assemble
In a small bowl, combine the 1 cup water, gravy base, cornflour, and a pinch of herb rub until smooth.
Pour the gravy mixture into the Dutch oven and stir to coat the meat and vegetables. Dollop the cheesy mashed potatoes on top and cover. Cook until warmed through.