Put all of the ingredients in the slow cooker and stir well.
Cook on low for 90 minutes.
Stir and serve.
Notes
Make sure to give everything a really good mix before turning the slow cooker on. This helps to ensure that the sauce is evenly mixed.
The key to this slow cooker mac and cheese turning out perfectly is know how your slow cooker cooks. Every slow cooker is different and some cook quicker than others, and others take a bit longer. You need the pasta to be cooked all the way through, but you don't want it to be mushy. It should still have a little bit of bite to it. If your slow cooker tends to cook things too quickly, then check it 30 minutes before the time is up, as it might already be done. Equally, if your slow cooker is a bit too slow, it might need 30 minutes more.
We stir the pasta once, maybe twice just to make sure the sauce is all mixed up and all the pasta is covered. However, don't keep opening up the slow cooker to take a look/smell, as you will let out all the moisture and that helps to prevent the pasta from going dry.
If you want to mix this recipe up a bit, then you can use parmesan and cheddar, or even add in some mozzarella too.
Try to avoid using pre-grated cheese. This is because they tend to add anti-caking agents and this will change the consistency of the sauce and it will be too gritty and not as melty.
Like a bit of spice in your meals? You can add a pinch of cayenne at the same time as the paprika, or even add a sprinkle of red chilli flakes before serving. We also love chipotle mac and cheese, where we swap the mustard for chipotle en adobo.