Pimento Sauce

Ingredients

• 2 tablespoons olive oil
• 5 shallots, finely sliced
• 1/2 cup mushrooms, sliced
• 1 teaspoon pureed garlic
• 1 teaspoon tomato paste
• 3/4 cup dry white wine
• 5 cups brown lamb stock, or canned beef broth
• 3 tablespoons pimento or roasted red pepper pureed in blender (with stock if necessary)
• 1 tablespoon unsalted butter, cold
• Salt and freshly ground black pepper