Cut the bread in tiny cubes and stir them in melted butter in an iron frying pan. Place in a low oven stirring occasionally until browned. Beat the egg with salt; garlic, and cayenne and add the oil a few drops at a time, beating until thick. Add the vinegar and beat well, then mix in the cheese. Pour over lettuce and toss. Add the bread cubes at the last moment. This is good with any salad greens, but especially with Bibb or Boston lettuce.