Once the onions are golden and tender, I add the beef broth and Worcestershire sauce. Let this simmer until it reduces slightly, absorbing all those delicious flavors—about 5-7 minutes should do it. While that’s simmering, I shape the ground beef into patties, seasoning them generously with salt and pepper.
In a separate skillet, I use a medium-high heat to cook the patties to your desired doneness—usually 4-5 minutes per side works for me. Just when these are almost done, I place a slice of cheese on top of each patty, allowing it to melt perfectly over the warm beef.
As everything comes together, I toast the burger buns on a baking sheet in the oven until they’re golden. Finally, I assemble the burgers by building a luscious foundation of that savory onion mixture on the bun, followed by the melty patty, and a few fresh thyme leaves for that extra pop of flavor.
Pro Tips for Best Results
I tested this three ways using different cheeses. Gruyère melted beautifully and added a wonderful nutty flavor, while Swiss brought a lighter touch. However, I’d recommend sticking with Gruyère for the best classic taste!
Also, don’t rush the caramelization process. Slow-cooking those onions until they’re deeply browned may take a little patience, but it’s absolutely worth it. Trust me, you’ll be rewarded with a depth of flavor that can’t be achieved otherwise.
Lastly, I’ve found that letting the cooked patties rest for just a minute or two before assembling the burger helps keep them juicy. This simple tip makes all the difference, and you won’t want to skip it!
Common Mistakes to Avoid
One mistake I made when I first experimented was not slicing the onions thin enough. Thicker slices make it harder for them to caramelize evenly, leading to some uneven textures in your dish. So, make sure to take your time with your knife. (See the next page below to continue…)