Heat the olive oil in a large wide pot over medium heat. Add the chicken and cook until browned, about 8 - 10 minutes, stirring every minute or two. Add the onion, potatoes, carrots, fennel, garlic, and celery and stir to combine. Cook until the onions have softened and become translucent, about 15 minutes, stirring every couple minutes.

Add the spices and stir to combine, cooking for another 5 minutes. Add the flour and stir to coat everything in the flour mixture, then add the broth and vinegar and stir to combine. Raise the heat to medium high to bring to a boil, then reduce back to medium and allow to boil until thickened, about 8 minutes, stirring every minute or so. Set aside and spread out in a large casserole pan to accelerate the cooling of the filling. Alternatively, you can keep the filling refrigerated overnight and assemble the pie the next day.

Grease a 9-inch pie pan and set it aside. Whisk the egg with vinegar and 3 tablespoons of ice water and set aside. Follow instructions below, depending on if you want to make the crust by hand, or if you want to use a food processor.

MANUAL METHOD: Mix together the flour, sugar, curry powder, salt, turmeric, garlic powder, and cream of tartar in a large wide bowl. Using a box grater, grate the butter using the large hole setting of the grater above the bowl, stopping to stir with a fork and coat the butter bits in the flour mixture every 10 seconds or so. When all the butter is in, pinch the mixture together with your fingertips until it resembles the texture of damp sand. Add the water, a tablespoon at a time, mixing it with a fork, until the dough just holds together when you squeeze a fistful of it in your hand.

FOOD PROCESSOR METHOD: In a small bowl, whisk together the egg, vinegar, and 3 tablespoons of the ice water. Set aside. Cut the butter into individual tablespoons and set aside. Place the flour, sugar, curry powder, salt, turmeric, garlic powder, and cream of tartar in the food processor and pulse a few times to mix together. Add the slices of butter and pulse until the butter is reduced to roughly pea-sized pieces. Run the machine while you add the egg mixture, letting it blend for 5 seconds after the liquid is added. Do NOT overmix. Add the remaining ice water, 1 tablespoon at a time, pulsing as you add it, until the dough just holds together. It shouldn't be too wet and sticky, nor should it be super crumbly.

Divide the dough into two equal portions, patting them into a rough circle shape about 1 inch thick. Cover one of them and place it in the refrigerator. On a lightly floured surface, roll out the other disc of dough until it is 1/8-inch thick and transfer it to the greased pie pan. Press the crust into the pan, trim off the excess leaving a 1-inch overhang (save the excess crust for decorations). Fold the 1-inch overhang under the edge of the crust all the way around. Cover and place the pan in the refrigerator.

On a lightly floured surface, roll out the smaller quantity of dough until it is 1/8-inch thick. Take the pie pan out of the refrigerator and add the filling to the pie. Cover the pie with the rolled out dough and press the edges together, and use a knife or a pizza cutter to cut off the excess dough (saving it for the decorations)

Combine the excess dough together in a ball (if it is dry, you can flick a few drops of water onto it to help it bind together). Roll out on a lightly floured surface, and cut out decorations to place on top if desired.

To make the daffodils, I just cut those out of the dough with a small knife with a couple stencils I made. It helps if you have a really daffodil to look at so you can see the shape of it. But basically, I drew a small eye shape (about 3/4-inch long) on a piece of parchment paper and cut it out, and that was each petal, and I used it as a stencil to cut around with a small sharp paring knife. For the center of the daffodil, I just cut out a small rectangle and then made the two furthest edges touch each other and pressed the seam together to create a hollow cylinder. And the long leaves and stem you can cut out freehand.

For the egg wash, whisk together the egg and milk. Lightly brush all exposed crust with the egg wash and place the whole pie in the freezer for 20 minutes to help the decorations firm up while you preheat the oven to 375 degrees Fahrenheit.

Place the pie in the center rack of the oven, and bake for 30 minutes before checking to see if foil is needed to prevent over-browning (the tips of the decorations can brown quickly). Cover the pie with foil if needed, then return it to the oven and bake for another 30 to 40 minutes, or until the crust is a deep gold color and the potatoes inside are tender. Remove and allow to cool for 30 minutes before slicing and serving.