In shallow medium bowl, add cornstarch and mix in salt and pepper. Dredge shrimp in it and shake off any excess
In large skillet, melt 2 tablespoon olive oil and 2 tablespoon butter over medium-high heat. Add shrimp in an even layer and cook for 2 minutes before flipping and cooking for another 2 minutes. Transfer shrimp to a plate.
Add the lemon juice, chicken stock and capers to skillet. Bring to boil, scraping up brown bits. Stir in the remaining 2 tablespoon butter. Add shrimp, tossing to coat and transfer to a plate. Pour sauce over shrimp and serve immediately.
Notes
Use wild shrimp when possible. It is healthier for you and just tastes better. Frozen shrimp works fine too but just make sure they're thawed before cooking.
Shrimp cook quickly so cook two minutes per side or until pink and opaque. If you cook too long, shrimp will be tough.
If you use pre-cooked shrimp, you want to cook just 30 seconds per side so they don't get overcooked.
While store-bought bottles can be quite convenient, they lack in flavor compared to the real thing. It really isn’t that much extra work to freshly squeeze the lemons and you’ll notice a difference in flavor.
If you like some heat, add ¼ to ½ teaspoon crushed red pepper flakes.