Cook the bacon slices to your liking. In the oven - preheat the oven to 400°F / 190°C. Place a wire rack over a foil wrapped baking tray. Lay out the bacon strips on the wire rack. Cook the bacon in the preheated oven for about 10 - 15 minutes, or until they are cooked to your liking. The time will vary depending on the thickness of the bacon. Remove the bacon from the oven and let it cool. Cut the bacon slices in half.
Butter a 9 x 13 dish. Place 6 slices of bread inside the dish. You can choose to cut the edges or not. Butter each of the bread slices.
Place the bacon over the bread slices. Top up with the cheese - about 2 slices over each slice of bread. Top with another slice of bread, and butter the top of each sandwich.
Whisk the milk and eggs together to make a smooth egg - milk mix. Add a generous pinch of salt and whisk to combine. Pour the egg mix evenly over the sandwiches. The egg mix should come half way up the sandwich casserole.
Leave for at least 20 minutes before baking. OR cover the dish with plastic wrap and leave it in the fridge for no more than 8 hours.
Preheat oven to 350°F / 180°C. Place the casserole in the oven (without the plastic wrap!), and bake for about 40 to 45 minutes - until the top is golden brown. Remove from the oven and let it cool slightly.
Cut and serve while warm.
Juice 3 mandarins, and remove the seeds. Slice the other 3 mandarins, and then transfer the juice and the slices into a large jug.
Add the gin and elderflower syrup into the jug. Pour 1 bottle of Middle Sister Red Blend wine into the jug and mix well to combine. Place the jug in fridge to chill overnight.