If using frozen shrimp, allow them to thaw so they release excess water and cook more quickly in the pan. 

If you're short on time, briefly place them in boiling salted water for 2 minutes, then drain with a sieve.

For fresh shrimp, simply clean and they're ready for cooking.

Chop the onion and garlic.

Heat oil in a pan, add onion and garlic, and sauté for about 1 minute on medium heat, making sure they don't burn.

Add the shrimp and cook for about 4-5 minutes, until their juices reduce.

This is how the shrimp should look once the juices have reduced.

Add the heavy cream and allow it to simmer for about 5 minutes.

Coat the butter in the flour, just enough to cover it.

Add it to the cream sauce, stir, and allow it to simmer until the sauce thickens slightly.

Season with salt and pepper, add chopped parsley, and turn off the heat.

Cook your favorite pasta according to the package instructions.

Toss the cooked pasta with the sauce in the pan or serve it separately, as shown in the picture. 

Enjoy the delicious shrimp pasta! 

Bon appetit!