Classic Espagnole Sauce
• Prep Time: 1 hour • Yields: 2 cups
1. Gather the ingredients. Fold the bay leaf, thyme, parsley stems and peppercorns in a square of cheesecloth and tie the corners with a piece of kitchen twine.
2. Leave one string long enough so that you can tie it to the handle of your pot to make it easier to retrieve.
3. In a heavy-duty medium saucepan, melt the butter over medium heat until it becomes frothy.
4. Add the mirepoix—onions, carrots, and celery—and sauté until lightly browned, about 6 minutes. Don't let it burn.
5. With a wooden spoon, stir the flour into the mirepoix a little bit at a time until it is fully incorporated and forms a thick paste (this is your roux).
6. Lower the heat to low and cook the roux, stirring, until it just starts to take on a very light brown color, 4 to 5 minutes. Again, don't let it burn.
7. Using a wire whisk, slowly add the stock and tomato purée, whisking vigorously to make sure it's free of lumps.
8. Bring to a boil, lower the heat to low, and add the sachet. Simmer until the total volume has reduced by 1/3 (you'll have about 2 cups), stirring frequently to make sure the sauce doesn't scorch at the bottom of the pan, 35 to 45 minutes.
9. Use a ladle to skim off any impurities that rise to the surface.
10. Remove the sauce from the heat, retrieve and discard the sachet.
11. For an extra smooth consistency, carefully pour the sauce through a wire mesh strainer lined with a piece of cheesecloth.
12. Keep the sauce covered and warm until you're ready to use it. If you won't be using it right away, cool it completely and refrigerate in an airtight container for up to 5 days.