Making this sheet pan macaroni can be broken down into three phases: 1. Boiling the macaroni until it's less than al dente. 2. Making a very thin bechamel using equal parts water and milk. 3. Baking it all together with a layer of garlicky, herbed, buttered breadcrumbs. Once you have the method down, you can get creative with the additions, cheeses, breadcrumb seasonings.