- In a medium pot, sauté the onions until translucent, add the mushrooms and cook for 2 more minutes. Remove from the pot and place aside.
- Place the butter into the pot and allow melting. Add the flour and stir vigorously until it forms a paste. Immediately add the beer and start stirring with a whisk until it becomes smooth.
- Add the onions and mushrooms back into the sauce and add the seasonings.
- Cook until it thickens slightly and served over the hamburger patty on a juicy hamburger!
*If mixture is too thick, add a few more drops of beer.