This mysterious, dark extraordinarily delicious sauce is a kind of gastrique, a relatively simple sauce based on caramelized sugar. Note that if the sugar turns black and begins to smoke, you have burned rather than caramelized it. Throw it out and start again, with lower heat and more patience this time. And if the caramel sticks to your pan and utensils when you’re done, boil some water in the pan, with the utensils in there if necessary. The caramel will loosen right away.
Recipe information
Yield
makes 4 servings
Ingredients
Preparation
Step 1
Preheat the oven to 450°F. Put the sugar in a heavy saucepan, preferably nonstick and with rounded sides, and turn the heat to medium. Cook, without stirring (just shake the pan occasionally to redistribute the sugar) until the sugar liquefies and begins to turn brown, about 10 minutes. Turn off the heat and carefully add the wine. Turn the heat to high and cook, stirring, until the caramel dissolves again. Then add the rosemary sprig and reduce over high heat, stirring occasionally, until the mixture is syrupy and reduced to just over 1/2 cup, 10 to 15 minutes.
Step 2
Heat a nonstick ovenproof skillet over high heat until it begins to smoke. Season the salmon on both sides with salt and pepper, then put it in the pan; immediately put the pan in the oven. Cook for 3 minutes, then turn the salmon and cook for another 3 minutes. Check to see that the salmon is medium-rare or thereabouts (it should be) and remove it and keep it warm, or cook for another minute or two if you like.
Step 3
When the sauce is reduced, stir in the balsamic vinegar and butter and turn the heat to medium-low. Cook until the butter melts, add some salt and pepper, and remove the rosemary sprig. Taste and adjust the seasoning, then serve over the fish, garnished with the chopped rosemary.
