I've never tried it in the crockpot, but the way we do it in the oven should turn out in the crockpot. I love mine best made with Velveeta. Layer cooked macaroni and slices of Velveeta, ending with the cheese as the top layer. Pour milk over the top of it (I don't measure, but a cup or so, depending on how much macaroni and Velveeta you use--play it by ear), then cook low. Like I said, I've never done it this way, so I don't know for sure if it will work right. If your insert is removable and can go in the oven, you may want to put it in the oven for a few minutes before supper to brown the top just a little.