In a medium saucepan, combine the wild rice, 1/4 teaspoon salt and 2 cups water and bring to a boil over high heat. Reduce the heat to a simmer, cover and cook until al dente, about 30 minutes. Drain the rice and set it aside.
In a large pot, melt the butter over medium-high heat. Add the carrots, celery, onion and a pinch of salt and cook until the vegetables are softened, 12 to 15 minutes. Stir in the flour and cook for 1 minute. Mix together the chicken stock and cream in a measuring cup. Add a third of the stock mixture to the pot and cook until thickened slightly, 3 to 4 minutes. Stir in another third of the mixture and cook another minute or two. Add the remaining third and cook until thickened, 3 to 4 minutes. The soup should coat the back of a spoon. Add the rosemary, black pepper and salt to taste. Taste and adjust the seasoning as desired.
Mix the butter crackers and olive oil in a bowl. Set aside.
In a 9-by-13-inch casserole dish, spread a third of the soup on the bottom of the dish. Spread half of the rice on top of the soup and follow with half of the shredded chicken spread across the rice. Repeat the layers, then top with the remaining third of the soup mixture. Top with the butter cracker mixture. Bake until bubbly, about 45 minutes. If the cracker topping is getting too browned, cover with foil.
Garnish with chopped parsley and serve with ketchup on the side!