Pre-heat the oven to 170°C/338°F.

Cut the beef into small thin pieces of about 1-1.5cm/⅜-⅝" thick.

Place the beef pieces and the chicken necks on a large baking tray, without overlapping, and bake in the oven for 45 minutes (note 3).

Heat oil in a frying pan over medium heat. Add garlic and onion pieces to the pan and sauté until the edges of the onion pieces start browning slightly.

Add the rest of the vegetables to the pan and sauté for a few minutes.

When there is no moisture on the bottom of the pan, add tomato paste and mix.

Add butter to the pan and mix well until the butter melts completely.

Add flour and mix well ensuring that there is no white flour left in the mixture.

Add wine to the pan and mix well, scraping the bottom of the pan to remove the flour stuck to it. Then, transfer the mixture to a large stock pot (note 4).

Transfer the cooked beef and chicken neck from the tray into the pot, including the juice in the tray.

Add 5L water to the pot (note 4) and bring it to a boil.

Reduce the heat to simmer and cook for 2-2.5 hours, occasionally removing scum as it rises, until the volume of the sauce reduces to about half (note 5).

Put the sauce through a fine sieve into a smaller pot. You need to do it in batches. Using a ladle or a spatula, squeeze the meat and vegetables in the sieve to get the sauce out of them as much as possible.

Bring the sauce in the pot to a boil, then reduce the heat to simmer. Cook for 40-60 minutes (note 6). You may occasionally stir the sauce using a spatula and scraping the bottom of the pot, in case the thickened sauce sticks to the bottom.

When the volume of the sauce reduces to 0.9-1L/1-1.1qt (note 7), turn the heat off and leave it overnight to develop the depth of the flavour.