Garnish
In a large skillet over medium-high heat, melt ¼ cup (60 ml) butter. Add garlic; cook, stirring for about 3 minutes until beginning to brown. Add chicken broth, lemon zest and juice, and bring to a boil. Remove from heat and let cool.
Fill a large stockpot with water and bring to a boil over high heat. Add pasta and cook for 2 minutes less than package directions, stirring occasionally until just done. Drain and rinse with cold water, tossing to cool quickly. Place back in pot.
Carefully toss about 9-inch portions of noodles into 3- to 4-inch (13- by 9-inch (33 by 23 cm) baking dish. Arrange frozen shrimp over noodles. Pour cooled sauce over, sprinkle with salt, pepper and hot pepper flakes, if using. Evenly arrange lemon slices over the top. Grate cold butter over. Sprinkle with additional parsley, if using.
Make it now
Preheat oven to 350°F (180°C). Bake in preheated broiler. Place baking dish on middle rack and broil for 3 minutes, until shrimp are lightly golden. Serve with a sprinkling of Parmesan cheese.
Make it a freezer meal
Wrap baking dish tightly with plastic wrap, pressing down gently to remove air. Cover with foil. Label and place in freezer.
Thaw and cook
Place baking dish in the refrigerator for at least 12 hours or up to 24 hours to thaw. Preheat oven to 350°F (180°C). Remove foil and plastic wrap, cover with new foil. Bake in preheated oven for 35 to 40 minutes, until shrimp just turn pink and opaque. Preheat broiler. Place dish on middle rack and broil for 3 minutes, until shrimp are lightly golden. Serve with a sprinkling of Parmesan cheese.
