Heat olive oil in a large skillet over medium-high heat.

When oil begins to release its aroma, add shrimp, salt, black pepper, and crushed red chile flakes. Cook shrimp on one side just until the tail of the shrimp is bright pink, approximately 1-2 minutes.

Turn shrimp over and squeeze lemon juice over top. Cook shrimp until all the gray color is gone and they are pink and cooked through, approximately 1 to 2 more minutes. At this point, shrimp should be coiled slightly tighter than when they were raw. Shrimp will continue to sizzle in the pan.

When they are cooked completely through, transfer shrimp to a serving platter, garnish with lemon zest, and serve immediately.