Start by preheating your oven to 170c (340f)
Break the chocolate into small pieces and place in a large heatproof mixing bowl. Then cut the butter into small chunks and add to the mixing bowl with the chocolate.
Put the sugar and water in a non-stick frypan and stir slightly to mix. Bring this to the boil over a medium heat. Be careful here, boiling sugar is extremely hot! Do not touch it or put a spoon in your mouth after it has touched the boiling sugar. Pour the boiling sugar syrup into the mixing bowl containing your chocolate and butter. Stir well until the butter and chocolate have both melted and you are left with a runny chocolate sauce.
Separate your eggs and add the egg yolks to the chocolate sauce one at a time, stirring each egg yolk in before adding the next. Finally add your ground almonds and stir until combined. Set this mixing bowl aside.
Take the egg whites and salt and whisk them to a firm meringue. In the time it takes you to do this the chocolate mix should have come to room temperature. Once the chocolate mix it at room temperature gently fold in the egg whites one third at a time. You want the egg whites to be incorporated but you need to do it gently over time rather than quickly stirring them in. The idea is to ensure you do not lose the air from the egg whites.
Once the egg whites are incorporated pour the mixture into your brownie tray and place in the oven for 30 minutes. After 30 minutes take the tray out of the oven and leave to cool on the bench for 5 minutes. After this 5 minutes of cooling you can turn the block of brownies out of the tray and leave to cool on a wire rack. Do not try to cut the brownies into squares until they are completely cool. This may take several hours.
Finally, these are very strong brownies! When you cut them make sure you only cut them into pieces that are two or three bites in size. Serve with tea or coffee and enjoy!