Preheat oven to 375 degrees.

Unthaw ground meat if needed then prepare the mashed potatoes. I don't peel the potatoes I just cut off the bad parts and leave the rest of the peels on. Cut into medium sized pieces and cover with water, simmer until potatoes fall apart very easily when pierced with a fork. Reserve the remaining water for later use. Mash the potatoes with hand masher and add enough of the reserved water to make potatoes creamy. Add salt to taste.

While the potatoes are cooking continue making the rest of the casserole. Sauté diced onion with the ground lamb, chopping up the ground lamb into small pieces as its cooking. Once all the meat is cooked and onions are softened, place it into a medium sized baking dish. Deglaze the pan with 1/2 cup broth and set liquid aside.

I used the same pan that I cooked the meat in, (cause who wants more dishes) simmer the chopped carrots and chopped turnips till softened, but not mushy. Drain any leftover liquid and layer veggies on top of the meat. Next add 2 cups frozen peas. Evenly pour the broth used to deglaze the pan over the veggies, plus an additional 1 cup broth and 1/2 cup white wine. Then sprinkle 1/2 cup arrowroot powder over the top. Last but not least spread mashed potatoes on top. Cook at 375 for 30 minutes or until the middle of the casserole is hot and bubbling.

Optional Topping: 1/2 Cup shredded cheddar cheese, fresh chives and parsley.