BALSAMIC VINEGAR SAUCE w/MUSHROOMS

By BobD

Ingredients

• 8 ounces unsalted butter
• 1 medium red onion, peeled and thinly sliced
• 2 cloves garlic, peeled and thinly sliced
• 8 shiitake mushroom stems
• 1 medium ripe tomato, coarsely chopped
• 1 bay leaf
• 1 teaspoon black peppercorns
• 1/3 cup balsamic vinegar
• 1/3 cup water
• Salt and freshly ground black pepper to taste

Details

Adapted from events.nytimes.com

Preparation

Step 1

Cut 6 tablespoons of the butter into 1/2-inch cubes. Refrigerate.

Melt the remaining butter in a large saucepan over medium heat. Add onion, garlic, mushroom stems, tomato and bay leaf. Cook, stirring occasionally, until the vegetables are soft but not brown, about 6 minutes.

Add vinegar and water. Reduce over medium high heat until just a syrupy liquid remains, about 8 minutes.

Lower the heat slightly. Whisk in the cold butter, 2 to 3 pieces at a time, allowing each addition to be absorbed before adding the next.

Strain through a fine sieve. Season with salt and pepper.

Keep warm over a double boiler.