Add the macaroni to the sauce and mix well ... but the bulk of your cheese should be an easy-melting variety (like cheddar, double gloucester, red leicester, gruyère, taleggio, Monterey Jack ...
Once all the milk is added, keep stirring, and bring the sauce to a gentle boil. Reduce the heat and simmer gently for 5 minutes. Season with salt and pepper. Stir in cheese and allow to melt.
Remove the pan from the heat and whisk in the yogurt. In a medium bowl, toss the cooked macaroni with the cheese sauce to coat thoroughly. Season with salt to taste. Pour the macaroni into the ...