First boil 4 of the eggs. Bring a pan of water to the boil, reduce the heat to a gentle simmer and delicately lower in 4 eggs. Cook for 6 minutes for yolks that are still a little runny. Lift the eggs into a bowl of iced water and leave to cool completely.
Meanwhile, put the sausage meat, mustard and herbs in a large bowl. Season with salt and pepper, then mix well with your hands and divide the mixture into 4 equal balls. Take three bowls: put the plain flour in one, the breadcrumbs in another, then crack the remaining 2 eggs into the third bowl and beat in the milk. Peel the boiled eggs.
Squash a sausage meat ball between 2 sheets of cling film (plastic wrap) and roll out with a rolling pin, or squash with the palm of your hand until it is large enough to encase an egg. Peel off the top layer of cling film. Roll one of the boiled eggs in the flour, then sit it in the middle of your rolled-out sausage meat. Lift the cling film, wrapping the sausage meat around the egg, and use your hands to mould the meat tightly and evenly around the egg. Remove the cling film and coat the scotch egg in flour, then the beaten egg/milk and lastly the breadcrumbs. Repeat with the remaining eggs.
To cook the scotch eggs, heat 10cm of oil in a wide saucepan, until a few breadcrumbs dropped into the hot oil turn golden after 10 seconds (or until the temperature reads 160°C on a probe thermometer. Lower the eggs into the oil and cook for 8–10 minutes, turning until golden and crispy. Drain on kitchen paper and keep, uncovered, in a cool place. I prefer to avoid having to put them in the fridge, so I try to fry my scotch eggs no more than 2 hours before a picnic.