Season Shrimp with salt and pepper. Mix well
In a pan add Olive oil. Once medium hot add shrimp(in two batches) to the pan in a single layer. Cook for 1-2 minutes each side till light brown in color.
To the same pan add butter. Few drops of oil. When butter starts to foam, add minced garlic. Sit for a couple of seconds.
Add all purpose flour. Stir till it looks light golden brown in color and the raw smell is gone.
Lower the flame. Slowly add warm chicken stock ,stirring continuously with other hand. Stir till there is no lumps.
Slowly add heavy cream followed by Parmesan cheese. Add onion powder and Italian seasoning. (If you find the sauce too thick add 1/2 cup warm chicken stock).
Add salt and pepper. Add cooked shrimp. Mix everything well using a spatula.
To the last add lemon juice.Mix well. Bring everything to a boil. Switch off the stove.
For making Pasta : Toss cooked pasta into the sauce (Add reserved pasta water if required to get desired consistency)