Bring a large pan of water to the boil with a tsp of salt and add the potatoes. Cook for 15 minutes until soft to touch with a fork. Once cooked, drain and place back into the pan, mash immediately and set to one side to cool.
In a medium sized sauce pan, place the haddock, bay leaf and milk to cover and bring to the boil. Simmer the fish for 1 minute and remove from heat leaving to cool for 2-3 minutes and then remove the haddock from the milk and leave to cool for a further 2 minutes. Once the fish is cool enough to handle, flake into the mashed potato along with fresh tarragon, parsley and the zest and juice of a lemon. Bring the mixture together using your hands and season with salt and white pepper. Lightly dust a baking tray with flour and spread over the fish and potato mixture, dusting another fine sprinkling of flour over the top. Leave to cool.
Bring a pan of water to the boil and place in 4 eggs. Cook for 5 minutes for soft boiled eggs. Once cooked, leave to one side to cool. Gently peel the eggs ready for making your Scotch Eggs!
Dust your hands with flour and take a quarter of the potato mixture. Flatted out into a 10cm round and place one of the peeled, soft boiled eggs in the middle. Work with potato mixture around the egg, making sure it's fully covered, and repeat with the remaining eggs.
Take 3 bowls, one for the egg mixture, one for the flour and one for the breadcrumbs. A little tip (use one hand for the wet ingredients and one for the dry, other wise things are going to get a bit messy!) Firstly, place your covered egg into the flour, egg and then into the breadcrumbs and repeat to ensure the potato is fully coated! Either place this into the fridge and leave over night, or if you're making these to serve straight away, prepare your deep-fat-fryer.
Pre-heat your over to 175ºc. Place the coated eggs into a hot deep-fat-fryer , cook until golden brown and then place on a baking tray into a hot oven and cook for a further 5 minutes.
Whilst the Scotch Eggs are in the oven, cook the asparagus in a pan of boiling water for 1 minute, drain, and add 25g salted butter, salt and pepper. Slice the scotch egg in half and season the egg with black pepper and serve with cooked asparagus.
For a gluten free variation, replace the flour with Doves Gluten Free and dry some Gluten Bread and blend to a fine crumb.