1. In a large skillet, melt butter over medium heat.

2. Add garlic to the skillet and sauté for 1 minute, or until fragrant.

3. Add the shrimp to the skillet, season with salt, pepper, and red chili flakes (if using). Cook for 2-3 minutes on one side, then flip and cook for an additional 1-2 minutes, or until shrimp are pink and opaque.

4. Remove from heat and stir in lemon juice and chopped parsley.

5. Serve immediately.