Yield: 2 servings
- 9-10 ounces ground chuck (more or less, depending on the size of your bread)
- Kosher salt
- 1 small onion
- 4 slices of rye bread
- 2 ounces Swiss-style cheese (Gruyere or Emmentaler are my favorites) -- sliced thin or grated
- 4 tablespoons butter (or more), softened
1. Form the beef into two oval patties slightly larger than the bread slices. Place on a rack and salt both sides heavily. Let rest for 10 minutes or so.
2. Slice the onion thin. Heat about a tablespoon of the butter in a small skillet. When it it stops foaming, add the onion slices. Sprinkle with salt and cook the onions, stirring occasionally, until they're beginning to brown (10-12 minutes). Set aside.
3. Heat a cast iron or other heavy skillet to medium high heat and coat the bottom of the skillet with oil.
4. While the burger pan heats, place a griddle or large skillet over medium low heat. Butter one side of each slice of bread and lay the slices, buttered side down, on the griddle. Distribute the cheese evenly over the 4 pieces of bread. Spread the onions over the cheese on two pieces of the bread -- not all 4, or final assembly is a mess.
5. While the bread begins to brown and the cheese melts, cook the beef patties however you like them. I think medium-rare to medium works best, which should take about 3 to 4 minutes per side.
6. When the meat is done, remove the patties to the rack and let them rest for a couple of minutes. Place a patty on each of the slices of bread with onions and top them with the other slices. If you've timed it right, the sandwich should need just another minute or so on each side for the cheese to melt completely and the bread to turn deep golden brown.