Heat the olive oil in a medium size skillet over medium to medium-high heat. Add the celery, onion, carrot and garlic; season with salt and pepper and sauté to soften, about 10 minutes, stirring frequently. Pour in the beer and stir. Let the beer reduce by half. Turn off the heat and let cool.
Meanwhile, soak the bread in milk and finely chop the corned beef. Place the corned beef and ground beef in a bowl and add the cheese. Wring out the bread and add it to the meat, crumbling it over the bowl. Pour in the beer mixture. Season with salt, pepper, mustard, cayenne and Worcestershire sauce. Add the eggs and mix with your hands.
Form the meat into a brick about 4 inches high on the baking sheet. Wrap the bacon slices across the top and around sides of the loaf. Bake for 1 hour in the middle of the oven, then switch on the broiler for about 5 minutes to crisp the bacon.