Set oven rack about 8 inches from the broiler element and start the broiler.
Mix together the panko breadcrumbs and the parmesan cheese in a small bowl, then drizzle in about a tablespoon of olive oil while stirring. Set aside.
Use a large, deep, oven safe skillet on medium high heat, add 1 tbsp each of butter and olive oil. Add the shrimp and cook until they begin turning pink. Add the minced garlic and toss the shrimp around until most are fully pink, 4 minutes. Remove the cooked shrimp from the skillet and set aside.
In the same skillet on medium heat add 3 tbsp butter. Once melted, stir in the flour and cook for 1 minute. Whisk in the milk and bring to a boil. Scrape up any browned bits on the bottom of the pan with a wooden spoon.
Add all the water to the skillet and bring to a boil, then add the macaroni. Cook for 7 or 8 minutes until the pasta is al dente.
Remove from the heat and stir in the grated cheese to melt. Next, add the cooked shrimp and combine. Taste and add salt and pepper as desired.
Sprinkle with the panko, parmesan mixture and place under the broiler until the crumbs begin to brown, about 2 minutes.
Serve hot with a side salad or vegetable of choice.