Compound butters are a mixture of butter and an addition of other ingredients, such as herbs but there are many more.
They make a really nice finishing touch and can be made ahead of time and stored in the freezer.
They can compliment a dish beautifully.
The general rule is 1 cup of butter and 1 tsp of your choice. Fresh herbs are a wonderful choice, as are garlic and chillies. Remember to give allergies consideration, so always have alternatives ready.
Mixing the butter with the additional ingredient, then rolling on parchment/baking paper and clingfilm and freezing and slicing as needed, three choices on a bread plate of garlic, sun-dried tomato and basil not only taste great they look beautiful too. There are some amazing small silicone moulds with shapes they work well as presentation, if you are good at piping then piped butter frozen on baking paper on a tray then added to a plastic container with layers of baking paper means you can store lots ahead of time and they don't take up much room. Just remember to allow enough time to take them out to defrost.
You can even do this for a sweet version which is really nice at breakfast time with pancakes or toast, try adding nuts and maple syrup or cinnamon, nutmeg and ginger.
Be realistic with how much you need and be prepared to bring more out during a meal if they are being devoured quickly.....yum! I think I can feel a baking session coming on to accompany all these lovely flavoured butters.