In a small bowl, combine the grated cheese and flour.

In a small saucepan, bring the milk, butter, and salt to a boil over medium heat.

Add the cheese and flour mixture to the saucepan, stirring until a semisoft ball forms.

Remove from heat and add the lightly beaten egg, whisking until the mixture is smooth.

Heat at least ½ inch of oil in a medium skillet over medium-high heat (or use a deep fryer set at 365°F) until a cube of bread turns light brown in 60 seconds.

Using the cup side of a spoon, cover each bread slice with 2 teaspoons of the cheese mixture, pressing it onto the bread to adhere well.

Place the canapés in the hot oil, cheese side down, and cook, turning once, until they turn golden brown.