- 1/4 cup vegetable oil
- 1 1/2 pounds white mushrooms, finely chopped
- Reserved Portobello mushroom stems, brushed clean
- 1/2 Spanish onion, coarsely chopped
- 2 teaspoons chopped garlic
- 2 cups dry white wine
- 1/2 cup soy sauce
- 1/2 cup dried mushrooms, such as porcini or shiitake ( 1/2 ounce)
- Pinch of salt
- 1/2 teaspoon herbes de Provence or thyme
- In a large nonreactive saucepan, heat the vegetable oil over moderately high heat. Add the white mushrooms, Portobello stems, onion and garlic and cook, stirring, until the mushrooms release their liquid, about 5 minutes.
- Add the wine, soy sauce, dried mushrooms, salt, herbes de Provence and 6 cups of water and bring to a boil. Cover, reduce the heat to moderate and simmer until the liquid is reduced to about 4 cups, about 1 hour.
- Pour the broth through a fine strainer into a heatproof bowl. Strain again, leaving any particles at the bottom of the bowl.
The broth can be refrigerated for up to 4 days.