Boil water in a pot. When the water starts to boil, add salt, cook the pasta, then drain in a sieve. Toss with oil to prevent drying.
While cooking the pasta, roughly mince the onion and carrot. Slice the mushrooms lengthwise. Cut the chicken and shrimp into bite-sizes.
Pour oil in a pot or a deep frying pan, and stir-fry the onion and carrot over medium heat. When the onion is translucent, add chicken and shrimp.
When the surface of the chicken turns white, add mushrooms, and stir thoroughly.
Turn down the heat to low. Add corn and butter. When the butter is melted and the ingredients are coated with butter...
Add flour, and mix together. The wooden spatula will feel a little bit heavy.
Pour in the milk in 2 batches. In the first batch, pour and blend in. Pour in the second batch until it thickens. Sprinkle salt and pepper.
Turn off the heat, add pasta from Step 1, and mix. If the pasta starts to stick together, separate while mixing.
Preheat the oven to 210℃ (410℉). When you are using a oven, set to the gratin setting. Pour the Step 8 mixture into a heatproof dish, and sprinkle pizza cheese and Parmesan cheese.
Bake in the oven for about 15 minutes, and it's finished Brown to your liking by adjusting the amount of cheese and temperature. Adjust the baking time to your oven.
Story Behind this Recipe
My mother has baked this gratin for years. This recipe makes 4 plentiful servings. It's a popular dish in our family.
You can add flour in 2 batches. When you add the milk, if the mixture is not thick enough, keep cooking until it becomes your preferred consistency. Make sure it's not too thick, because the pasta absorbs liquid from the sauce. I usually cook this dish with ingredients I have at home, and I've replaced chicken meat for bacon.