Microwave frozen butternut squash for a minute to defrost before blending. It's already blanched, so there is no need to cook it.

I usually buy a 12-ounce jar of whole roasted red peppers, which typically contains two peppers, and I use one of them. Make sure to drain the water off the pepper well.

If you have a high-speed blender—the kind that can cook soup—you don't need to soak the cashews. If you have a regular blender, soak the cashews for several hours until they are plump and soft to the touch. Take a look at the Guide to Soaking Cashews for quicker ways of softening cashews that may suit you.

This cheese sauce may appear thin right after blending, but it will naturally thicken slightly as it rests, thanks to the small amount of corn starch. No need to add more starch, which can taste bad - just give it time to set after heating for the perfect consistency. If it's still too thin, put it in a pan, and heat it up on a low simmer for 5 minutes.

For the best flavor, cooking off the cornstarch taste is important—heat is key to making it disappear. If your blender doesn’t heat liquids, add the mixture to a pot and gently simmer for a few minutes on low. Be sure not to crank the heat up, as it could cause clumping—low and slow is the way to go.

If a skin forms on the surface as the sauce cools, just stir it back in, and it’ll disappear. Once the sauce has fully cooled, the skin won’t form anymore.

Nutritional information is only an estimate.