PREPARATION:
- Combine flour and 1/4 teaspoon salt on pastry board, cutting board or countertop; make well in center. Whisk 3 eggs, milk and oil in small bowl until well blended; gradually pour into well in flour mixture while mixing with fingertips or fork to form ball of dough.
- Place dough on lightly floured surface; flatten slightly. To knead dough, fold dough in half toward you and press dough away from you with heels of hands. Give dough a quarter turn and continue folding, pushing and turning. Continue kneading 5 minutes or until smooth and elastic, adding more flour to prevent sticking if necessary. Wrap dough in plastic wrap; set aside. Allow dough to stand at least 15 minutes.
- Combine chicken, spinach, prosciutto and remaining egg in medium bowl; mix well. Add 2 tablespoons cheese, 1 tablespoon cream, remaining 1/4 teaspoon salt and pepper to spinach mixture; mix well.
- Unwrap dough and knead briefly (as described in step 2) on lightly floured surface; divide into 3 pieces. Using lightly floured rolling pin, roll out 1 dough piece to 1/16-inch thickness on lightly floured surface. (Keep remaining dough pieces wrapped in plastic wrap to prevent drying.) Cut out dough circles with 2-inch round cutter. Cover rolled dough with clean kitchen towel to prevent drying while working.
- Place 1/2 teaspoon chicken filling in center of 1 dough circle; brush edge of circle lightly with water. Fold circle in half to enclose filling, making sure all air has been pushed out. Pinch outside edges together firmly to seal.
- Brush end of half circle with water; wrap around finger overlapping ends. Pinch to seal. Place tortellini on clean kitchen towel. Repeat with remaining dough circles, rerolling dough scraps as needed. Repeat with remaining 2 dough pieces and chicken filling. Let tortellini dry on towel for 30 minutes before cooking.
- Heat butter in 3-quart saucepan over medium heat until melted and bubbly; cook and stir mushrooms in hot butter 3 minutes. Stir in remaining cream. Bring to a boil over medium heat; immediately reduce heat to low. Simmer, uncovered, 3 minutes. Stir in remaining 1/3 cup cheese; cook and stir 1 minute. Remove from heat.
- Cook tortellini, 1/3 at a time, in large pot of boiling salted water 2 to 3 minutes just until al dente. Drain well; add to mushroom-cream sauce. Bring mushroom-cream sauce and tortellini just to a boil over medium heat; reduce heat to low. Simmer 2 minutes. Sprinkle with parsley. Serve immediately.
