1/4 cup finely chopped shallot
1 garlic clove, peeled, crushed and chopped
5 tablespoons extra-virgin olive oil, divided
2 cups broth (either vegetable or chicken)
4 ripe Roma-style tomatoes, seeded and chopped
1 fresh thyme sprig
2 tablespoons lemon juice
4 tablespoons butter
2 tablespoons balsamic vinegar
2 tablespoons red-wine vinegar
Salt and pepper, to taste

In a skillet, saute the shallot and garlic in 1 tablespoon of the olive oil over medium-low heat. Add the broth and simmer until liquid has reduced to 1/2 cup. (To determine what level broth will be at when it has reduced to 1/2 cup, first fill pan with 1/2 cup water, then stick a chopstick or knife into liquid, touching pan's bottom, and mark liquid's depth on chopstick or knife.)

Add the tomatoes and thyme sprig to skillet and cook until liquid from tomatoes has mostly reduced and thickened a bit.

Meanwhile, heat the lemon juice with 1 tablespoon water, then whisk in the butter.

Scrape tomato mixture into a blender jar. Add the vinegars and blend briefly, just to puree tomatoes. Scrape tomato mixture into a small bowl, then whisk in butter mixture and remaining 4 tablespoons olive oil. Adjust seasonings by adding additional vinegar, olive oil, a bit of butter and the salt and pepper, to taste.

Makes about 2 cups.

— Recipe adapted from "Sauces: Classical and Contemporary Sauce Making," by James Peterson.