Boil the crayfish for 5-10 minutes until bright red. Remove the head and pincers and reserve. Remove the tail meat from the tail and set aside.
In a stone mortar and pestle, grind the heads and pincers into a fine paste. (OPTIONAL: Skip this step if you don't have a mortar and pestle and discard the heads and pincers.)
In a large cast iron dutch oven, melt two tablespoons of butter until frothy. Add the chopped onion and saute until tender, about 10 minutes - then add the roughly chopped garlic and thyme and saute until fragrant, about another 5 minutes.
Add the shellfish paste and stir until. Cook until softened, another 5-10 minutes. Then add the crayfish tails to the pot. Season with salt and pepper, to taste.
Deglaze the pot with a splash of dry white wine. Scrape up the browning bits. Then add the bay leaves and chicken broth. Bring the stew to a simmer.
Add half of the fresh chopped dill and stir. Season with salt and pepper to taste.
Thicken the chowder with the remaining butter and heavy cream. Add the remaining dill and remove from the heat. Give it one final seasoning of salt and pepper, to taste. Serve with crusty bread and TOSS A COIN TO YOUR WITCHER, O VALLEY OF PLENTY!