½ cup finely grated Gruyère cheese
¾ teaspoon dried sage
¾ teaspoon dried oregano
¼ teaspoon pepper
1 puff pastry sheet, thawed
2 tablespoons honey mustard
2 ounces packaged sliced pepperoni
1 egg, lightly beaten
Mix the Gruyère, sage, oregano, and pepper together in a small bowl. lLay the puff pastry on a lightly floured surface with a short side closest to you. Cut in half crosswise. Arrange a long side closest to you. Divide the mustard and spread evenly over the sheets of puff pastry, leaving a 1-inch border at the top edge. Divide the pepperoni and arrange in a single layer over the mustard. Top with the Gruyère mixture. Brush the farthest edge of each half with the egg. Roll the puff pastry tightly from the closest edge toward the egg-coated edge. Lay, seam-side down, on a baking sheet and chill until firm, about 30 minutes.
Preheat oven to 400ºF.
Cut the logs into ¼-inch thick slices and arrange, cut-side down, 1 inch apart on a foil or parchment lined baking sheet. Bake, one baking sheet at a time, in the middle of the oven until golden, about 14 minutes. Serve warm.
do-ahead tip: The puff pastry can be filled and rolled up to 1 day in advance and refrigerated, or frozen up to 2 weeks in advance. Thaw, cut, and bake as directed.