Source: Bon Appétit
Notes: I have never make the apple salad, though it sounds absolutely delicious and the perfect complement for such a sandwich. Also, I go with about 2 oz. of cheese per sandwich, though I can’t imagine 4 oz being so bad.
Update: I now brown the bread a little differently thanks to a tip left by Trina — thank you! — in the comments. These changes apply to step 2. First, I spread one half of each slice of bread I with mayonnaise — it doesn’t burn as easily as butter, and the bread browns evenly every time. Second, instead of using butter in the pan, I use about a tablespoon of grapeseed oil — the high smoke point prevents it from burning. Butter, of course, works, but this is my preferred method these days.
- 4 tablespoons unsalted butter, divided
- 3/4 cup 1/4-inch-thick sliced shallots
- 1 teaspoon fresh thyme leaves
- Kosher salt and freshly ground black pepper
- 4 1/2-inch-thick white bread, peasant bread is highly recommended
- mayonnaise, see notes above
- 8 ounces Gruyère or Comté sliced 1/8-inch thick
for the apple salad:
- 2 cups arugula
- 1/2 apple (such as Pink Lady or Fuji), cut into 1/4-inch slices
- 2 tablespoons fresh lemon juice
- 2 tablespoons extra-virgin olive oil
- Preheat oven to 400°F. Heat 2 tablespoons butter in a small saucepan over medium heat. When butter begins to foam, add shallots and thyme; season with salt and pepper. Cook, stirring continuously with a wooden spoon or spatula, until shallots begin to soften and caramelize, 4–5 minutes; remove from heat and set aside.
- Heat a large heavy-bottomed skillet over medium heat. Working in 2 batches, add 1 Tbsp. butter and swirl in pan to melt butter and coat bottom of pan. Spread a little mayonnaise on one side of each slice of bread. Add 2 slices of bread to pan and cook until golden brown and crisp on the bottom, 2–3 minutes. Transfer bread, toasted side down, to a rimmed baking sheet. Repeat with remaining butter and bread slices. Divide cheese evenly among bread slices; top cheese with reserved shallots.
- Place baking sheet in oven and bake until cheese is melted, 7–8 minutes.
- Combine arugula, apple slices, lemon juice, and oil in a large bowl; toss to coat and evenly distribute. Season salad to taste with salt and pepper.
- Press 2 pieces of bread together, melted cheese sides in; halve sandwich on a diagonal and place on a plate. Repeat with remaining bread slices. Divide salad between plates.