It is a reduction sauce, the easiest, most malleable sauce a cook can make.
Although it is not essential, most reduction sauces are finished with a bit of butter, oil or cream to add smoothness and even more flavor.
There are any number of ways to enhance a reduction sauce.
But it can take on a more elegant air if you finish it with a reduction sauce.
In today's home cooking, not only soups but also reduction sauces, risotto and many low-fat preparations rely on stock for much of their flavor.
And the custard is no richer in flavor than a reduction sauce finished with butter and cream.
Fillets of beef dressed with a rich, brown reduction sauce arrived perfectly medium-rare, accompanied by an amazingly light onion-potato custard.
Little slices of fried artichoke and braised bitter greens in a reduction sauce undercut the almost dangerous richness of the squash.
"Personally, I would prefer to do it as a reduction sauce."
You could cut the richness of the lamb with an acidic reduction sauce, but I find that a squeeze of fresh lemon does the trick even better.