Spanish sauce

Ingredients:

• 110 g unsalted butter
• 0.5 cups flour
• 1 small carrot, finely chopped
• 1 stalk celery, chopped
• 1 small yellow onion, finely chopped
• 1 tbsp tomato paste
• 0.5 cups dry white wine
• 8 cups of good-quality, low-salt beef broth
• 1 teaspoon black peppercorns
• 4 sprigs of fresh parsley
• 4 sprigs of fresh thyme
• 2 dried bay leaves

Preparation:

1. In a large saucepan, melt the butter over medium-low heat. Stir in the flour until smooth. Cook, stirring frequently with a wooden spoon and reducing the heat as needed to prevent burning, until the roux is a few shades darker than the peanut butter, 18–20 minutes.
2. Add the carrots, celery, and onion and cook, stirring occasionally, until the onion begins to soften, about 3 minutes. Add the tomato paste, then whisk in the white wine and cook until the sauce thickens, 1 to 2 minutes. Don't worry if the vegetables get stuck in the whisk; as you add more liquid, they will blend into the sauce. Whisk in the broth, 1 cup at a time, and reduce the heat.
3. To make the bouquet garni, place peppercorns, parsley, thyme, and bay leaf in a square of cheesecloth and tie with kitchen twine. Drop the bouquet garni into the sauce. Simmer the sauce, skimming off any fat or foam from the surface with a spoon, until it has reduced by half and has reached the consistency of gravy, 30–45 minutes.
4. Remove the sauce bag from the sauce, then strain the sauce through a fine-mesh sieve or cheesecloth. Use as a base for other sauces. The sauce can be stored in a tightly sealed container in the refrigerator for up to 1 week. Or, divide into four smaller containers and store for up to 6 months.