Roast Beef, Blue Cheese, and Onion Jam Panini Recipe

Ingredients

• ½ cup crumbled blue cheese
• 1 tablespoon mayonnaise
• 1½ teaspoons prepared horseradish, or to taste
• 12 large ½-inch-thick slices country-style white bread
• 6 ounces thinly sliced high-quality roast beef
• 1 Granny Smith apple, unpeeled, cored, and sliced paper thin
• 3 tablespoons salted butter, softened

1. In a small bowl, stir the blue cheese, mayonnaise, and horseradish together, mashing the cheese with a fork until the mixture is almost smooth. Store in the refrigerator, covered, for up to 3 days, if desired. Return to room temperature before using.
2. Place 6 slices of the bread on a work surface, and spread each with 1 heaping tablespoon of the blue cheese spread. Divide the roast beef and apple among the bread slices, covering each evenly. Spread about 1 tablespoon of the Onion Jam over the top of each. Set the remaining bread slices on top. Generously butter the tops and bottoms of the panini.
3. Heat a Lodge 12-inch cast iron grill pan over high heat. Working in batches, arrange the panini on the hot surface, and weigh down the top with a cast iron grill press or skillet or by pressing with a metal spatula. Toast, turning once, until the bread is browned, about 5 minutes per side. Serve warm with the remaining Onion Jam on the side.
Onion Jam
4. Makes: 2 cups Ingredients:
   • 6 tablespoons (¾ stick) salted butter
   • 2 pounds yellow onions, halved lengthwise and thinly sliced
   • ¼ cup firmly packed light brown sugar
   • ¼ cup red wine
   • 1 tablespoon balsamic vinegar
   • 2 teaspoons finely chopped fresh rosemary
   • Kosher salt and freshly ground black pepper
   Directions:
   1. Melt the butter in a Lodge 12-inch cast iron skillet over medium heat. Add the onions, and stir to coat. Cover the skillet, and cook, stirring occasionally, until the onions are completely limp, about 15 minutes.
   2. Uncover the skillet, and reduce the heat to medium-low. Cook, stirring often to scrape up the brown glaze that forms on the bottom of the skillet, until the onions are very soft and golden brown, about 25 minutes more.
   3. Add the brown sugar, wine, and vinegar. Stir until the sugar dissolves and the liquid cooks away, about 5 minutes.
   4. Remove from the heat. Stir in the rosemary, and season with salt and pepper to taste. Set aside to cool to room temperature. Store in the refrigerator, covered, for up to 1 week.