ONE: Who knew both rosemary and thyme were so distinctly fantastic for baking? And two: Who knew rosemary and thyme were so easily interchangeable in all those cookies, crisps, cobblers, even flan?
Put a batch of rosemary or thyme cookies in the oven, and the wintry herbal-floral aromas that fill the kitchen are a crisscross of butter, sugar and a toasty bouquet garni. Rosemary, with hints of pine and lemon, and slightly minty thyme (they're both members of the mint family) are known for pulling up the flavors of roasted meat or fish; accenting the saltiness in sauces; and defining the vegetable-garden tastes of tomatoes, peppers and onions.
But they work just as fabulously in desserts: creamy custards or panna cotta; buttery cookies; and pies, crisps and cobblers made with fall fruit such as apples and pears.
Like lemon zest or ginger used in baking, rosemary and thyme focus the elements in fruit that aren't sweet while tempering the sugars. But the two herbs add their own pungent, piney nuances.
Add finely chopped, fresh rosemary or thyme leaves to rolled-out butter cookies, and the fragrant herbs play off vanilla bean seeds and
fleur de sel
in the batter. The herb-flecked cookies are simultaneously savory and sweet.
Despite the strong essential oils in rosemary leaves, you can use the same amount of either rosemary or thyme in the cookies. Same with cobblers and crisps. A pear crisp gets a butter-flour-brown sugar topping with a tiny bit of ground ginger and a couple of spoonfuls of either fresh chopped rosemary or thyme leaves. The herbs scent the pears in the crisp, mingling with the vanilla and lemon juice that are mixed in with the fruit.
For a creamy, luxurious flan, bruised sprigs of the herbs (with the leaves and stems) are infused in a milk and cream mixture for 1 hour, and the flavor of rosemary becomes much stronger than the flavor of thyme. So, in this case, you would use more thyme than rosemary in the recipe. Once the flan is baked, it's allowed to cool, then refrigerated overnight, and the flavor of the herb becomes a little stronger.
The flan's layer of unctuous, sweet caramel is especially delicious with the creamy, herbal custard. Now you know.