Cook the Pasta
Bring a large pot of water to a rolling boil. Salt the water lightly. Add the angel hair pasta and cook for about 4 minutes, or until al dente (still a little firm). Drain and set aside.

Cook the Shrimp
In a large, heavy skillet set over medium heat, melt the butter. Once it begins to bubble gently, add the shrimp in an even layer. Sauté for about 1 minute on each side, until they just turn pink. Remove the shrimp with a slotted spoon and set aside, leaving the butter in the pan.

Build the Sauce Base
To the butter still in the pan, add the minced garlic and cook for about 1 minute, stirring so it doesn’t burn. Then sprinkle in the flour and Cajun seasoning. Stir continuously for about 5 minutes—this cooks the flour so the sauce won’t taste raw and allows the Cajun spices to bloom.

Whisk In Milk and Thicken
Gradually whisk in the milk, a little at a time, to avoid lumps. Continue stirring over medium heat until the sauce thickens—this may take a few minutes.

Season and Finish
Remove the sauce from heat, then season with salt and the fresh lemon juice. Stir in the cooked shrimp.

Combine & Serve
Spoon the creamy Cajun sauce and shrimp over the cooked angel hair pasta. Toss gently so the pasta is well-coated with sauce. Serve hot.