
Clean and rinse the shrimp, then devein them. Pat them dry with paper towels.
Mix the flour and cayenne pepper together in a large bowl. Add the shrimp and toss a few times to lightly coat them with the flour mixture.
Heat a sauté pan and add the butter. Once the butter melts, add the olive oil. Stir in the garlic and sauté lightly until fragrant, then add the shrimp to the pan. Sauté the shrimp, then add the white wine, salt, sugar, fish sauce (if using) and black pepper.
Continue to stir until the shrimp are cooked through. Dish out and serve immediately with rice and lemon wedges.