-
1
Pour boiling-hot water over porcini in a bowl and let stand until softened, about 20 minutes.
-
2
Lift out porcini, squeezing excess liquid back into bowl, and rinse to remove any grit.
-
3
Finely chop porcini.
-
4
Pour soaking liquid through a sieve lined with a dampened paper towel into another bowl and reserve.
-
5
Trim leek, reserving about 5 inches of green leaves, and rinse greens well.
-
6
Halve rest of leek lengthwise, then rinse well under cold water and pat dry.
-
7
Coarsely chop greens and finely chop white and pale green parts, reserving greens separately.
-
8
Finely grate enough cheese to measure 1/4 cup, then cut off and reserve rind.
-
9
Reserve remaining piece of cheese.
-
10
Pulse cremini caps, shiitake caps, 1/3 cup chopped porcini, white and pale green parts of leek, garlic, and 1/2 teaspoon salt in a food processor until finely minced.
-
11
Heat butter in a 12-inch nonstick skillet over moderate heat until foam subsides, then cook mushroom mixture, stirring constantly, until liquid mushrooms give off is evaporated and mushrooms are golden, about 10 minutes.
-
12
Transfer to a bowl and cool completely.
-
13
Stir in 1/4 cup grated cheese, 1 tablespoon parsley, and salt and pepper to taste.
-
14
Tuck parsley and thyme sprigs into celery and tie together tightly with string to make a bouquet garni.
-
15
Bring cold water, beef broth, bouquet garni, cracked peppercorns, cremini stems, shiitake stems, leek greens, remaining chopped porcini, porcini soaking liquid, cheese rind, and remaining 1/4 teaspoon salt to a simmer in a 3-quart heavy saucepan, stirring occasionally.
-
16
Reduce heat and cook at a bare simmer, partially covered, 45 minutes.
-
17
Pour broth through a large sieve lined with a double thickness of rinsed and squeezed cheesecloth (or dampened paper towels) into a large bowl, pressing on and discarding solids.
-
18
Return broth to saucepan.
-
19
Set smooth rollers of pasta maker at widest setting.
-
20
Cut pasta dough into 4 pieces and keep 3 pieces covered.
-
21
Flatten unwrapped piece of dough into a rectangle and feed through rollers.
-
22
Fold rectangle in half and feed through rollers 8 more times, folding in half each time and dusting with flour as necessary to prevent sticking.
-
23
Turn dial to next (narrower) setting and feed dough through without folding.
-
24
Continue to feed dough through without folding, making space between rollers narrower each time, until narrowest setting is used.
-
25
(Cut sheet of dough in half if it gets too long.)
-
26
Cut out as many rounds as possible from sheet with cookie cutter (reserve trimmings for another use, such as chicken noodle soup).
-
27
Transfer rounds in 1 layer to a lightly floured wax-paper-lined baking sheet and cover with plastic wrap.
-
28
Working with 5 pasta rounds at a time, put 1/4 teaspoon filling in center of each round, keeping remaining rounds covered tightly with plastic wrap.
-
29
Moisten edges of filling-topped rounds with a fingertip dipped in water and fold in half, letting bottom edge protrude slightly beyond top edge, then press top edge to bottom half to seal.
-
30
Holding straight edge of half-moon against nail of your little finger, wrap half-moon around fingertip (which will cause curved edge to flip up), overlapping corners and pinching to seal.
-
31
Transfer tortellini to a dry kitchen towel (not terry cloth).
-
32
Roll out and cut remaining dough and make more tortellini in same manner, working with 1 piece at a time.
-
33
Bring broth to a boil and season with salt and pepper.
-
34
Add tortellini and cook at a strong simmer, stirring gently once or twice, until tender, 3 to 5 minutes.
-
35
Ladle broth with 8 to 10 tortellini per person into bowls and serve remaining piece of Parmigiano-Reggiano on the side for grating.
