Place the macaroni in a 9 x 5-inch microwave-safe glass loaf pan. Add enough water just to cover the pasta.
In a 950-watt microwave oven, cook on high for 5 minutes, stopping the microwave for a few seconds if the pasta begins to foam over the dish, then continuing to cook as directed. The pasta should be almost tender and the water almost gone. Carefully drain out any excess (but very hot!) water.
Whisk the milk, egg yolk, mustard, thyme, salt, and pepper in a small bowl until uniform. Pour over the macaroni; add the Canadian bacon and cheese. Stir well.
Microwave on high for 4 minutes, pausing the microwave twice as the pasta cooks to stir thoroughly, until the pasta is almost tender, with some chew left. Set aside at room temperature for 5 minutes, stirring occasionally, before serving.