Even if you just grow herbs in containers on a windowsill, things can get out of hand. Hardy herbs like mint, parsley and thyme can really grow quickly, perhaps to the point that you can't use them all quickly enough. 

In Eastern Canada, there's a tradition among the Acadians called les herbes salées. Quite simply, this is combining fresh herbs with salt. The salt draws out moisture from the herbs, making them less prone to spoilage.


The salted herbs can then be used in the way that you would use salt and herbs independently -- in soups and stews, on eggs, basically with anything. 

According to Joel at Well Preserved, traditionalists would say that there's a specific set of herbs that make up the mixture, including parsley, chervil, onion, finely diced carrot and celery leaves. Possibly, the original mix is similar to the French fines herbes -- usually parsley, chervil, tarragon and chives. However, you can use any herbs you like or have on hand. In addition, just as celery leaves make a nice addition, the carrot greens can be very finely chopped and used as well, and they give a very pleasant, grassy aroma. 

The easiest method to make herbes salées is to lay a thin layer of salt in the bottom of a clean quart mason jar. Chop your herbs, mix, and lay down a layer in the jar. Sprinkle more salt on the herbs, then another layer of herbs, and so on. You'll want to use about 1/4 cup of kosher or sea salt for every cup of herbs.

Give the jar a shake to distribute, and keep in the refrigerator. Your herbs will keep for weeks, or even longer. 

If you want to take it a step farther, you can greatly increase the proportion of salt to herbs, roughly equal, and in thin layers. This will ultimately desiccate the herbs, and the dry mix can be kept at room temperature. This is effectively a homemade form of bouillon.