Directions

1. Bring a large pot of water to a boil over high; season generously with salt. Add tortellini, and cook for 1 minute less than package directions, about 4 minutes. Remove 1 cup cooking water from pot, and set aside; drain remaining water. Set tortellini aside.
2. Place egg yolks in a medium bowl; add 3/4 teaspoon salt, and whisk to loosen. Set aside. Melt butter in a large high-sided skillet over medium. Add garlic, and cook, stirring constantly, until fragrant, about 1 minute. Add cream, and bring to a simmer over medium. Reduce heat to medium-low. Using a large spoon in one hand and a whisk in other hand, add some of simmering cream to egg yolk mixture, and whisk constantly to temper eggs. Add another spoonful of hot cream to egg mixture, and continue to whisk constantly. Repeat process until eggs are liquidy and bowl is hot. Add egg mixture to skillet with remaining cream mixture. Cook over medium, stirring often, until thickened, about 2 minutes. Reduce heat to low, and whisk in cheese, about 1/4 cup at a time, until smooth, about 5 minutes.
3. Remove cream mixture from heat; add chicken and cooked tortellini, stirring until combined. Add 1/4 to 1/2 cup reserved cooking water until desired consistency is reached, adding more reserved cooking water as needed. Sprinkle with parsley, thyme, lemon zest, and black pepper. Serve immediately.