Place all ingredients in a small microwave-proof bowl or jug.
Heat on medium power for 20-second bursts in the microwave, stirring/whisking well after each burst, until the butter is melted and the sauce is smooth and velvety. (In my microwave this process takes 3 bursts). You don't want to overheat the cream, ie you just want it warm enough to melt the butter this will give you a thick sauce.
Serve
Notes
Let's be honest this is a very simple recipe so not much can go wrong
If your sauce is very thin, it just means the cream got a bit hot, no worries, leave the sauce to cool and it will start thickening up.
Store leftover sauce in the refrigerator for up to 4 days. Warm it with a couple of bursts in the microwave when you want to serve it again.
Garlic powder: You can use garlic powder or garlic granules, I find fresh garlic is too strong in this recipe as the cooking time for this sauce is so short.
Parsley: Fresh parsley or dried parsley is fine to use.