In a small saucepan gently warm the ale, set aside. Take another small saucepan and over a medium heat melt the butter until it begins to foam, tip in the flour and stir everything together, cooking for 1 min. Whisk in the warm ale in several additions to create a thick sauce then whisk through the cheese to create a thick paste. Stir the mustard, Worcestershire and chives through the sauce.

Heat a grill to its highest setting. Place the slices of bread on a flat baking sheet and grill on one side until golden brown. Flip the bread over and spread each one with the cheese mixture. Place back under the grill and cook for a further 1-2 mins or until golden brown and bubbling, serve immediately.