Toast bread on one side only in oven broiler. Separate egg yolk and white. Whip egg white until it forms stiff peaks.
With soup spoon or fingers, scoop out about 1-2" circle in middle of un-toasted side of bread and drop yolk in. (Make sure you don't break through the toasted side of the bread.) Sprinkle grated cheese liberally over bread and egg yolk. Spread whipped egg white over entire un-toasted bread slice with egg yolk in middle. Depending on the size of the slice, this should pile up to about 1" high.
Bake in 350 degrees F oven approximately 10 minutes till meringue is lightly browned. A little salt and pepper before baking if you like.