Smen is an aged butter made throughout Middle East, particularly in Morocco. It turned the necessity of preserving butter in warm climates into a culinary creation.
It smells like a stinky cheese, and is used in small amounts as a condiment for flavour, particularly in couscous and in tangine dishes, and in some pastries.
To make Smen, clarified butter, dried herbs and salt are put in small earthenware pots. Some additional flavouring such as cinnamon may be added; some additional body such as a bit of semolina may be used. It is then stored in a cool, dry place to mature. Sometimes, it is even sealed and aged for years, even buried under ground.
The butter will have started off being made from milk from sheep, goats, buffalo milk (in Egypt), or cow.
Melt 1/2 pound (250 g) unsalted butter. Put 1 teaspoon dried oregano in a tea ball, or tied up in cheesecloth, add to butter, gently simmer for about 25 minutes or until butter is clarified (the butter will go clear, with a white layer on the bottom.) Skim off any foam using the edge of a piece of paper towelling, discard the oregano, and strain the butter through a double layer of cheesecloth. Stir in 1/2 teaspoon salt. Transfer to a clean container, ideally sterilized. Cover and refrigerate. Let age for at least 2 weeks before using, and use up within 6 months. If you use salted butter, omit the salt.
1 part butter, 1 part olive oil