Preheat oven to 350F.
Prick the potatoes with a fork and microwave on high for 5 or 6 minutes.
Microwave another 5 min. Pierce with knife to check if they are cooked.
Remove from microwave. Cut off the tops and scoop out the center using a spoon, leaving a thin skin
Place the potato scooped out in a bowl.
Add milk, butter and salt and mash until smooth.
Meanwhile, make the filling. Heat the olive oil in a large fry pan over medium high heat.
Add onion and garlic, sauté for 2 minutes until softened.
Add lamb and cook, until nicely browned about 3 minutes.
Sprinkle flour over meat and stir to combine.
Add stock, water, salt, pepper, Worcestershire sauce, thyme & oregano & stir to combine
Bring to simmer and continue to stir until the sauce is thick and glossy – around 2 minutes.
Add frozen carrots and peas.
Remove from heat.
Fill each potato with the Filling so it is slightly heaped. Push down lightly to pack the filling in well.
Scoop the mashed potato with a spoon then fluff it up with a fork.
Place in the oven and bake for 15 to 20 min until the mashed potato is starting to brown on the ridges.