Crack the eggs into a shallow dish, add the milk, season generously and mix well to combine. Cut the ciabatta loaf into four even-sized pieces and then cut each one open so that you have eight separate pieces. Place each piece of the bread, cut-side down in the egg mixture. Leave to soak for a minute before turning over.
Heat a large frying pan and add half of the oil, then add the soaked bases of ciabatta, cut- side down. Cook over a medium to low heat for about 1-2 minutes until golden brown, then turn over and cook for another two minutes.
Meanwhile, preheat the grill. Arrange the bacon on a grill rack and cook for a couple of minutes on each side until really crispy. Keep warm.Remove the ciabatta bases from the frying pan and keep warm. Add the remaining oil and then add the tops of the ciabatta. Cook as described above.
Mix together the mustard and the mayonnaise in a small bowl. Just before serving, spread the half the mustard mayonnaise over the bases, next add a little ketchup, the rocket, a layer of tomato slices and season with the black pepper. Top with the bacon. Finish by spreading the remaining mustard mayonnaise on to the top half of the eggy bread. Arrange on warmed plates and serve immediately.