Mushroom Soup
3½ Lbs Fresh White Mushrooms
½ Cup Plus 2 Tbsp Unsalted Butter
¾ Cup Madeira
9 Cups Water
½ Oz (¾ Cup) Dried Porcini
½ Lb Baking Potato
2½ Tsp Salt
1/3 Cup Heavy Cream
1 Tsp White Pepper
Quarter 1½ Pounds White Mushrooms (about 9 Cups Quartered), Then Pulse In A Food Processor In 2 Batches Until Finely Chopped. Melt ¼ Cup Butter In A 5 – 6 Quart Heavy Pot Over Moderately High Heat Until Foam Subsides, Then Sauté Chopped Mushrooms, Stirring Occasionally, Until Liquid From Mushrooms Is
Evaporated, 10 - 15 Minutes.
Add Madeira & Boil, Stirring Occasionally, Until All Of Liquid Is Evaporated, 5 - 8 Minutes. Add Water & Dried Porcini & Bring To A Boil, Then Reduce Heat & Simmer, Uncovered, Stirring Occasionally,
45 Minutes.
Pour Through A Sieve Lined With A Coffee Filter Or Dampened Paper Towel Into A Large Bowl, Pressing Hard On Solids & Then Discarding Them. Skim Off Any Fat.
If Stock Measures Less Than 8 Cups, Add Water. If More, Boil, Uncovered, In Cleaned Pot Until Reduced To 8 Cups.
Cut Remaining 2 Lb Mushrooms Into ¼ Inch Thick Slices (about 11 Cups Sliced).
Peel Potato & Cut Crosswise Into ¼ Inch Thick Slices, Then Transfer To A Bowl & Cover With Water.
Heat Remaining 6 Tablespoons Butter In A 5 – 6 Quart Heavy Pot Over Moderately High Heat Until Foam Subsides, Then Cook Mushrooms With 1 Teaspoon Salt, Stirring Occasionally, Until Mushrooms Are Very Tender But Not Browned, About 15 Minutes (mushrooms Will Exude Liquid).
Drain Potato & Add To Mushrooms Along With Mushroom Stock. Bring To A Boil, Then Reduce Heat & Simmer, Uncovered, Until Potato Is Very Tender, About 10 Minutes. Add Cream & Bring Just To A Boil, Then Remove From Heat.
Transfer Soup To A Large Metal Bowl, Then Purée In Batches In A Blender Until Very Smooth, About 1 Minute Per Batch (use Caution When Blending Hot Liquids).
Return Soup As Puréed To Cleaned Pot & Bring To A Boil. Stir In White Pepper & Remaining 1½ Teaspoon Salt. Season With Additional Salt If Desired.
Soup Can Be Made Ahead & Cooled Completely, Then Chilled, Covered, 3 Days Or Frozen In An Airtight Container 1 Month.
Bring To A Boil Just Before Serving.
Makes 16 Servings.