Make a sunny-side up egg. The one in the picture was microwaved for a minute. If you cook it in the microwave, use a toothpick to poke a hole in the yolk.

Combine the flour and butter in a bowl and microwave to melt. Once melted, mix the flour and butter. I usually microwave it at 500 W for 30 seconds.

Once well-mixed, add half of the milk and mix it up. Microwave for 30 seconds!

Add the remaining milk, mix well, and microwave for another 30 seconds! Mix well. At this thickness, it's good for pasta or gratin dishes.

This time, we're using it to top bread, so keep heating and mixing until nice and thick. For me, this usually takes just 30 more seconds. Lastly, mix in the soy sauce.

Top the bread with ham and all the white sauce. The sauce seems a bit thick, but when you eat it, it won't drip.

Top with the egg and cheese. You can use sliced cheese or pizza cheese.

It's ready when the cheese has melted. If you want your croque-madame to stay flavorful, be careful not to toast it for too long.