SAUCE SOUBISE (ONION SAUCE)
About ¾ cup
For fish, veal, sweetbreads, lamb, or main-course vegetables.
Combine in a medium heavy saucepan over medium-low heat:
- 1 large onion, chopped
- 2 tablespoons butter
Cover and cook, stirring occasionally, until the onions are tender but not browned, about 25 minutes. Stir in:
- 2 tablespoons all-purpose flour
Cook, stirring, until smooth, about 1 ½ minutes. Whisk in:
- 1 cup milk
Bring to a simmer and cook, stirring frequently, until thick, 1 to 2 minutes. Strain through a medium-mesh sieve into a small saucepan. The sauce will be thick. Set over low heat and slowly whisk in until the desired consistency is reached:
- 2 to 4 tablespoons heavy cream or milk
Season with:
- Salt and white pepper to taste
- Pinch of grated or ground nutmeg