Heat the olive oil in a large saucepan and fry the onion and garlic until cooked, but not browned.
Add the lamb and stir until it is thoroughly cooked and browned.
Add the beef stock, tin/can of chopped tomatoes and grated carrots (optional). Mix.
Reduce the heat to a simmer. Simmer uncovered for 10 minutes while making the mashed cauliflower topping. Let the liquid evaporate so the mince thickens.
Boil the cauliflower until soft, this takes about 8-10 minutes.
Drain and allow ALL the steam to escape. Too much water left in the saucepan will make a 'sloppy' mash.
Add the butter, salt, pepper and cream. Using a stick blender with a blade attachment, puree until smooth.
Place the shepherd's pie mince/ground meat mix in the bottom of a large casserole dish. Top with the cauliflower mash then sprinkle on the cheese.
Put the casserole dish on a baking try to catch any liquid that may bubble over.
Bake at 180C/350F for 20 minutes and until the cheese is browned.
