To Make Potato Topping: Place diced potatoes in a medium saucepan. Cover with water and place over high heat. Allow to come to a boil. Boil for 15 minutes, or until potatoes are tender. Drain.
Meanwhile, make meat filling by placing a large skillet over medium heat. Add butter, garlic and onion, mixed herbs, and parsley. Cook til onion is just becoming translucent, then crumble in ground beef and saute 1 minute. Add peas and carrots then continue to saute until meat is no longer pink and onion begins to brown, about 5 minutes. Mix in flour.
In a small bowl, combine beef broth, wine, wooster and ketchup. Mix together, then add to beef mixture. Add salt and pepper to taste. Lower heat and simmer mixture for 15 minutes, stirring occasionally, until almost all of liquid has been absorbed. Spoon mixture into a large casserole dish.
Mash potatoes until smooth, then add butter followed by milk. Whip until fluffy. Add salt and pepper to taste. Spread potatoes over beef filling. Sprinkle with grated Cheddar cheese. Use dubliners or another aged or sharp cheddar for a nice touch.
Bake in preheated oven for 25 minutes, until top is browned and cheese is bubbly.
