Ingredients

• 8 thin slices prosciutto (about 3 ounces)
• 8 1/2 "-thick slices Pullman bread
• 8 ounces Fontina cheese, thinly sliced
• 3/4 cup trimmed chopped watercress
• 1/4 cup unsalted butter, room temperature

Instructions

1. Preheat oven to 350°F. Bake prosciutto on a parchment-lined baking sheet until it darkens and shrinks slightly, 6-8 minutes. Let cool (meat will crisp as it cools).
2. Top 4 slices of bread with half of cheese, prosciutto (breaking to fit), watercress, then remaining cheese (it will bind as it melts) and bread; butter tops.
3. Heat a large skillet over medium heat. Working in 2 batches, cook sandwiches, butter side down, pressing firmly, until bottom is golden brown. Butter tops, turn, and cook until golden brown and cheese is melted, about 4 minutes. Transfer to a wire rack; let cool slightly. Remove crusts and cut each sandwich into 4 triangles.