Ingredients
Scale
- 2 medium yellow onions, peeled cut in half and sliced into 1/4-inch thick semi-circles
- 3 tablespoon unsalted butter, softened, plus more for buttering the bread
- 1 tablespoon olive oil
- 1 scant teaspoon kosher salt
- 1 heaping teaspoon fresh thyme leaves
- 1/2 teaspoon fresh cracked black pepper
- pinch of granulated sugar
- 3–4 tablespoons beef broth, beer, or white wine to deglaze the pan
- 1/2 cup finely shredded Gruyere cheese, please use more cheese to your own taste
- 4 slices bread, or more depending on how many sandwiches you’d like to make
Instructions
- Place a medium, heavy bottom sauce pan over medium heat. Add the butter and olive oil and stir until butter is melted. Add the sliced onions all at once. Stir to coat the onions in the fat. Allow onions to cook, undisturbed, for about 4 minutes. Add salt, thyme, and pepper and stir. Place lid on the pan and allow to onions to cook for about 4 minutes at a time. Lower the heat if the onions are browning too quickly. Remove the lid to stir the onions every so often. The onions will begin to brown, break down, and resemble an onion jam.
- When onions are entirely browned and completely soft, add your liquid (beef broth, beer, wine, or water) to the pan. Using a wooden spoon, scrape any burned bits off the bottom of the pan as the liquid evaporates. This takes about 30 seconds. Remove pan from heat and allow to rest while you assemble the sandwiches.
- Butter one side of each slice of bread. On the unbuttered side add a good sprinkling of gruyere, top with warm onion mixture, top with more cheese and the final piece of sandwich bread. Repeat process in assembling the other sandwich.
- Cook sandwiches over medium heat in a medium saute pan. Flip and cook until golden on the outside and melty on the inside. Place sandwich on a cutting board. Allow the sandwiches to cool for 2 to 3 minutes before slicing. Enjoy warm!