Directions:

1. Remove legs from crayfish and set aside. Remove the crayfish tail, cut in half, and remove the flesh, refrigerate with the legs until needed. Break the tail shell and crayfish head into roughly 3cm pieces and place in a large saucepan over medium heat.Add the shallot, thyme, and butter, and cook for 5 minutes, stirring regularly. Add the flour and cook for a further 2 minutes. Stir through the tomato paste and cook, stirring constantly for 2 minutes. Add brandy to deglaze pan, then slowly add stock and mix well. Increase the heat to high and bring to the boil. Allow to boil for 2 minutes, then stir and remove from the heat.

2. Meanwhile, bloom the gelatine by sprinkling the gelatine into 2 tablespoons of water. Set aside.

3. Strain stock mixture through a muslin cloth into a clean saucepan to remove solids. Place over medium-low heat, add the gelatine and salt, and stir to dissolve. Gently simmer for 1 minute, remove from heat and set aside to cool to room temperature.

4. Whisk crème fraiche and cream together to form soft peaks. When the crayfish mix is cool, gently fold in the cream.

5. Finely chop half the crayfish meat and fold into the mousse mixture. Pour the mousse into a 700-millilitre-capacity mould or divide between smaller bowls. Cover and refrigerate overnight.

6. To serve, loosen mousse from the mould by briefly dipping the base in hot water, then invert onto a serving plate. Generously spoon caviar over the top of the mousse and garnish with dill sprigs. Add reserved crayfish meat and legs to the plate and serve with crackers, melba toast or crusty bread.