Clean and devein shrimp using a scissor and a toothpick (refer to the video for demo).
In a pan over medium heat, melt the butter.
Add the garlic then sauté until fragrant.
Add the onion then sauté for 1 more minute.
Add the shrimp. Season with salt and pepper. Stir and cook until the shrimp changes in color.
Add chili garlic oil if you want it to be spicy. Stir and cook for another 1 minute.
Turn off heat then transfer to a serving bowl.
Serve while hot and enjoy your garlic butter shrimp!