Begin by warming a large skillet over medium heat. Once hot, pour in the olive oil, allowing it to evenly coat the bottom of the pan.
Add the unsalted butter to the skillet. Let it melt completely, swirling the pan gently to merge the oil and butter together seamlessly.
Once the butter has transformed into a luscious liquid, introduce the minced garlic and red pepper flakes into the skillet. Sauté for approximately 1-2 minutes, stirring occasionally, until the garlic becomes fragrant and starts to turn a light golden color. Be careful not to burn the garlic!
Raise the heat to medium-high and carefully place the shrimp in the skillet in a single layer. Allow them to cook undisturbed for 2-3 minutes until they turn vibrant pink and opaque on one side.
Turn the shrimp over gently using tongs or a spatula, then pour in the fresh lemon juice. Season generously with salt and freshly cracked black pepper to taste. Continue to cook for an additional 1-2 minutes until the shrimp are fully cooked and succulent.
Remove the skillet from the heat, and sprinkle the freshly chopped parsley over the shrimp, adding a burst of flavor and color for garnish.
Serve the spicy garlic butter shrimp immediately while still hot. Pair it with crusty artisan bread for dipping, or serve it over a fluffy bed of rice for a satisfying and complete meal.