Preheat the oven to 375°F.
Layout the bread on a baking sheet and toast in the oven until crunchy and golden brown. In the meantime heat 1/2 of the oil in a non-stick pan. Sauté the celery, carrot, and onion until soft, about 8 minutes. Then mix the vegetables with the bread, thyme, sage, salt and pepper.
Place the stuffing mixture into an 8x8 baking dish (or appropriately sized oven safe vessel for the amount of portions you are making). Mix in about 1/3 of the broth, (may not need it all, the amount of broth should not exceed the top of the bread) let sit for 10 minutes. Press the bread into the bottom of the baking dish and bake in the oven for 15-20 minutes until the broth is absorbed. Then set aside.
In the meantime, in a pot of salted boiling water boil the potatoes until a fork can easily slide in and out, about 8-10 minutes. Melt the butter in a saucepan over low heat and add the cream to warm. Mash up the potatoes and add in the butter and cream. Whip until smooth. Season with salt and pepper to taste and set aside.
Heat the remaining oil in a sauté pan, add the turkey and brown while breaking it up into smaller pieces. Stir in the flour, cook for 2 minutes. Season with salt and pepper. Stir in the remaining broth and the peas. Simmer for 10 minutes until the broth thickens. Taste and adjust the seasoning with salt.
Preheat the oven broiler on high.
Pour the turkey mixture over the stuffing, top with mashed potatoes. Place under the broiler until golden brown. Let sit for 5 minutes before portioning. Serve with crusty bread.