Step 1

Leave small mushrooms whole, halve medium-size mushrooms, and quarter large mushrooms (12 cups). In a very large skillet heat 1 tablespoon of the walnut oil and 11/2 teaspoons of the butter over medium heat. Add 6 cups of the mushrooms; cook about 5 minutes or until the mushrooms begin to color, stirring occasionally. Using a slotted spoon, transfer mushrooms to a large bowl. Repeat with the remaining mushrooms, oil, and butter. Add the shallots, garlic, and reserved cooked mushrooms to the skillet; cook and stir for 2 to 3 minutes more or until the mushrooms are golden and the shallots are tender. Stir in salt and pepper.

Step 2

Remove from heat; add the Madeira. Return to heat; simmer about 3 minutes or until the liquid is nearly evaporated. Stir in the cream, chives, and rosemary. Cook about 2 minutes or until cream is slightly thickened. Remove from heat and let stand for 5 minutes. Transfer to a serving bowl and sprinkle with snipped fresh parsley; serve warm.