In a large bowl, add pressed garlic, Worcestershire sauce, honey, and Guinness beer. Let Guinness foam settle down and slowly whisk ingredients together until combined.
In a large zip-lock bag, add chicken drumsticks and pour in the Honey Guinness sauce. Let chicken marinade for 15-20 minutes.
Preheat the oven to 375.
Preheat an oven-safe cooking pan (or a skillet) over medium-high heat and add some canola oil for cooking.
Slice onions and add them to the pan.
Take out the chicken drumsticks and place them into the hot pan to sear. Sear chicken drumsticks on all sides for a few minutes.
Pour in the sauce, bring to simmer and transfer into the preheated oven.
Cook for 35-40 minutes, depending on thickness of drumsticks.