Preheat oven to 180 C / Gas 4. Line a small pie dish with half of the bacon. Dice the remaining bacon.
Mix flour and stock; add minced liver, onion, garlic and remaining bacon. Add beaten egg, cream, salt and pepper, parsley, mixed herbs and anchovy essence (if using). Pour into a blender and pulse to a smooth paste.
Pour into pie dish lined with bacon. Cook in preheated oven for 1 hour and 10 minutes.