Instructions:

Preheat oven to 375 degrees.

Cook macaroni according to package directions.

Cut shrimp crosswise into thirds. In a medium frying pan, over medium heat, melt 2 tablespoons butter. Add garlic; cook until translucent; add onion and celery, cook, stirring occasionally, until translucent. Add shrimp, 1 teaspoon seasoning salt, chives and pepper. Mix thoroughly reduce heat and cover. Cook for 10-12 minutes until shrimp is cooked through. Drain and reserve liquid.

In a medium saucepan, melt 2 tablespoons butter. Stir in cornstarch/water mixture, nutmeg, 1 teaspoon salt. Gradually stir in half & half; cook and stir until mixture thickens slightly and bubbles. Remove from heat. Add 1 cup cheese; stir until melted; add second cup of cheese. Continue to stir until mixture is smooth. Add reserved liquid from shrimp; continue to stir until mixture is smooth.

Grease 2-quart casserole with remaining tablespoon butter. In large bowl combine shrimp and cooked macaroni; add cheese sauce mixture and mix thoroughly. Pour mixture into casserole dish. Stir in egg. Bake 35-40 minutes or until lightly browned and bubbly. Add remaining cup of shredded cheddar cheese. Bake until cheese is melted. Remove from oven. Sprinkle paprika across the top if desired. Let stand 10-15 minutes before serving.