
A classic British dish! Use ground beef for Cottage pie and ground lamb for Shepherd's pie. Use a sharp cheddar, preferably English if you can.
In a medium sized skillet, heat the oil until shimmering. Add onions and cook 2-3 minutes. Add the mushrooms, ground lamb or beef, stirring to break it up about 5 minutes.
Add garlic, thyme and Worcestershire sauce. Saute until meat is no longer pink.
add beef broth, carrots and peas. Cook until broth is reduced and veggies are cooked
Season to taste with salt and pepper
Put meat mixure into a casserole dish. (You can also use a souffle dish or oval baking dish...something between 8"x8" and 13"x9").
Top with 1/2 cup cheddar cheese.
Spread or pipe mashed potatoes and top with remaining grated cheese. You'll want ridges or peaks in the potatoes. Top with remaining shredded cheese.
Cover with foil and bake at 350 degrees F. for 45 minutes or until hot and bubbly and cheese is melted.