1. Cut the liver and the bacon into strips about 2in (6cm) long and ½ in (1.5cm) wide.

2. Heat 1 tbsp each oil and butter in a large frying pan over medium heat. Add the shallots and cook, stirring frequently, for 5 minutes, or until golden. Transfer to a plate.

3. Add the remaining oil and butter to the pan and increase the heat to high. Add the liver and bacon and cook for 3-4 minutes, until the liver is seared and slightly pink inside.

4. Return the shallots to the pan. Pour in the vermouth, and boil, scraping up any browned bits in the pan with a wooden spoon, for 1–2 minutes.

5. Reduce the heat to medium-low and stir in the mustard and the Worcestershire sauce (if using). Season with salt and pepper and serve at once.

Variation

Lamb's Liver and Bacon

Use the same quantity of lamb's liver. Add a dash of Tabasco sauce for an extra touch of spice.