Sauce Base for Steak Diane—Demi-glace | America's Test Kitchen

Ingredients

• 2 tablespoons vegetable oil
• 4 teaspoons tomato paste
• 2 small onions, chopped medium (about 1 1/3 cups)
• 1 medium carrot, chopped medium (about 1/2 cup)
• 4 medium cloves garlic, peeled
• 1/4 cup water
• 4 teaspoons unbleached all-purpose flour
• 1 1/2 cups dry red wine
• 3 1/2 cups low-sodium beef broth
• 1 3/4 cups low-sodium chicken broth
• 2 teaspoons black peppercorns
• 8 sprigs fresh thyme
• 2 bay leaves