Leftover herbs. It’s hard to know what to do with them and I hate to see them go to waste. Parsley butter is a great way to use them and it gives an elegant twist to many simple dishes which can be served on the side, or as separate courses. For example:
Over lowish heat: sauté mushrooms in parsley butter until juices have been released and evaporated. Adjust seasoning and acidity (lemon, S&P). Serve.
An alternative to the above is to cook the mushrooms in extra virgin olive oil first and then add some parsley butter within the last couple of minutes of cooking. The flavour is quite different. The following can also be fried in parsley butter with good results: diced carrots (low heat for 30 or 40 minutes), potatoes (chopped to 1cm cubes, though in this case I would suggest cooking them in oil first), whole asparagus tips, or whole green beans.
If you’re concerned about your health, check out this video of Dave Asprey eating a stick of butter and talking about the health benefits. You could also go the extra mile and make your own cultured butter. Here’s a recipe.