Rinse shrimp in cool running water and lightly pat dry. Stir the shrimp, garlic, salt, pepper, flour and butter gently together in a covered container. Allow to marinate in the fridge for at least one hour. Remove from fridge and let sit at room temperature for approximately 30 minutes.
Heat a sauté pan over medium-high until hot. Pour contents of container into pan and sauté shrimp for about 3 minutes on each side. Once the garlic begins to brown, turn off heat. Remove the shrimp immediately and serve with the rice and lemon wedge. Spoon the extra sauce over the rice and shrimp.