Add butter to saucepan and melt gradually over low heat.
Slowly add garlic, onion powder and flour so that it is evenly distributed around the pan. Whisk slowly for 5-10 minutes.
Every couple minutes, give the pan a shake and swirl so that the gravy covers the entire bottom of the pan.
Add broth 1/2 cup at a time until gravy becomes a dark, rich brown color.
Turn to medium heat and allow to simmer until you have your desired thickness. Stir every 20-30 seconds while simmering. Cook for 8 minutes for thinner gravy and up to 12 minutes for thick gravy.
Stir in a Tablepsoon of butter at the end to add sheen. Remove from heat.
