Stick to your bones Shepherd's or Cottage Pie. The tradition is that if using ground lamb it is called Shepherd's pie, if using ground beef it is called Cottage Pie. This is something that is served at our local Irish Pubs. My husband loving it so much requested me to make it at home.
Boil potatoes in salted water until potatoes are very tender. Drain potatoes and add milk, butter, salt to taste and cheese. Mash just until blended, set aside.
In non stick skillet brown ground meat. Drain any access fat if not using lean meat and transfer to a bowl and set aside. In same skillet melt butter and sautee onion for 5 minutes. Add mushrooms and pinch of salt, cook until mushrooms are golden. Then add minced garlic and cook for 1 minute. Add meat back into pan, mix around and then mix in flour to make a simple rue. Cook for 5 minutes. Add beef broth and simmer until thickened and reduced, about 10 minutes or so. Add peas and carrots.
Place filling into a 4 quart baking dish.
Layer mashed potatoes on top of filling and spread evenly around with tip of fork. Top with 1 cup of shredded cheddar cheese and bake in oven at 375'F for 40 minutes and crust is golden brown.