Dry the Shrimp: Pat the shrimp very dry with paper towels so they sear instead of steam. Season lightly with salt if desired.
Sear Until Pink: Heat the vegetable oil in a wide skillet over medium-high heat. Add the shrimp in a single layer and sear for 2 to 3 minutes per side, until pink, lightly caramelized, and just opaque. Transfer to a plate.
Wake the Garlic: Reduce the heat to medium and add the minced garlic to the same skillet. Stir briefly until fragrant, keeping it pale and aromatic.
Reduce the Glaze: Stir in the sweet chili sauce, soy sauce, lime juice, and crushed red pepper flakes if using. Let the mixture simmer for 1 to 2 minutes, until glossy and slightly thickened.
Coat and Finish: Return the shrimp to the skillet and toss gently until every piece is coated in the sweet chili garlic sauce.
Garnish and Serve: Serve immediately with green onions and sesame seeds if using.